diff --git a/python/paddle/base/data_feeder.py b/python/paddle/base/data_feeder.py
index d4800aac174f25540e8d19c10cff68ee7e3eaf4e..b8044dc2b788522cac22c8627e86b4d655259996 100644
--- a/python/paddle/base/data_feeder.py
+++ b/python/paddle/base/data_feeder.py
@@ -143,13 +143,13 @@ def check_type(input, input_name, expected_type, op_name, extra_message=''):
     if in_dygraph_mode():
         return
 
-    # NOTE: `in_declarative_mode` is used to determined whether this op is called under
+    # NOTE: `in_to_static_mode` is used to determined whether this op is called under
     # @to_static in transformation from dygrah to static layer. We add Tensor in
     # expected_type to skip checking because Tensor may be created and used in unusual way.
-    from .dygraph.base import in_declarative_mode
+    from .dygraph.base import in_to_static_mode
 
     # Need a better design to be fix this.
-    if in_declarative_mode():
+    if in_to_static_mode():
         if not isinstance(expected_type, tuple):
             expected_type = (expected_type,)
         expected_type += (core.eager.Tensor,)
diff --git a/python/paddle/base/dygraph/base.py b/python/paddle/base/dygraph/base.py
index 06922ef9bd281774aca08ffb523ba8709e73c2c9..6490a6152cef1314cf578ee413436b55a2926189 100644
--- a/python/paddle/base/dygraph/base.py
+++ b/python/paddle/base/dygraph/base.py
@@ -13,8 +13,6 @@
 # limitations under the License.
 from ..wrapped_decorator import signature_safe_contextmanager, wrap_decorator
 import decorator
-import contextlib
-import functools
 import inspect
 import sys
 import numpy as np
@@ -23,7 +21,6 @@ from paddle.base import framework
 from paddle.base.framework import global_var
 from paddle.base.multiprocess_utils import CleanupFuncRegistrar
 from .tracer import Tracer
-import logging
 from ..data_feeder import convert_dtype
 import warnings
 from ..framework import _get_paddle_place
@@ -44,15 +41,19 @@ __all__ = [
 NON_PERSISTABLE_VAR_NAME_SUFFIX = "__non_persistable"
 
 
-def in_declarative_mode():
+def in_to_static_mode():
     """
     Return a bool value that indicates whether running code under `@to_static`
 
     """
-    return global_var._in_declarative_mode_
+    return global_var._in_to_static_mode_
 
 
-def declarative_unsupport_argument_warning(
+# TODO(Aurelius84): Need to remove this alias after clean usage in PaddleX
+in_declarative_mode = in_to_static_mode
+
+
+def to_static_unsupport_argument_warning(
     func_name, input_names, inputs, support_values
 ):
     """
@@ -81,12 +82,12 @@ switch_to_static_graph = wrap_decorator(_switch_to_static_graph_)
 
 
 @signature_safe_contextmanager
-def _switch_declarative_mode_guard_(is_declarative=True):
+def _to_static_mode_guard_(is_to_static=True):
     global global_var
-    original_val = global_var._in_declarative_mode_
-    global_var._in_declarative_mode_ = is_declarative
+    original_val = global_var._in_to_static_mode_
+    global_var._in_to_static_mode_ = is_to_static
     yield
-    global_var._in_declarative_mode_ = original_val
+    global_var._in_to_static_mode_ = original_val
 
 
 @signature_safe_contextmanager
@@ -105,7 +106,7 @@ def program_desc_tracing_guard(enable):
 @signature_safe_contextmanager
 def param_guard(parameters):
     # Note: parameters is a reference of self._parameters or self._buffers
-    if in_declarative_mode() and not paddle.in_dynamic_mode() and parameters:
+    if in_to_static_mode() and not paddle.in_dynamic_mode() and parameters:
         try:
             origin_parameters = parameters.copy()
             for name, var_base in parameters.items():
@@ -322,7 +323,7 @@ def no_grad(func=None):
         test_layer()
 
     """
-    if in_declarative_mode():
+    if in_to_static_mode():
         warnings.warn(
             "paddle.no_grad is only supported for inference model, and not supported for training under @to_static."
         )
@@ -732,12 +733,12 @@ def grad(
             grad_y1 = paddle.to_tensor(3.0)
             print(test_dygraph_grad([grad_y1, grad_value])) # [24.]
     '''
-    if in_declarative_mode():
+    if in_to_static_mode():
         # In dy2static context, we call static interface `gradients`
         # to calculate grads.
         from paddle.static import gradients
 
-        declarative_unsupport_argument_warning(
+        to_static_unsupport_argument_warning(
             "paddle.grad",
             ["retain_graph", "create_grad", "only_inputs", "allow_unused"],
             [retain_graph, create_graph, only_inputs, allow_unused],
diff --git a/python/paddle/base/framework.py b/python/paddle/base/framework.py
index 2fe4b5ce4a1040dd00c195ed20969f7675056ea7..117912c4f18943c90d42a36bbe8c0a148f9818d4 100644
--- a/python/paddle/base/framework.py
+++ b/python/paddle/base/framework.py
@@ -84,15 +84,13 @@ class GlobalThreadLocal(threading.local):
         TODO(xiongkun): how to access another thread local data ?
         """
         global _dygraph_tracer_
-        self._in_declarative_mode_ = False
+        self._in_to_static_mode_ = False
         self._functional_dygraph_context_manager = None
         self._dygraph_tracer_ = _dygraph_tracer_
 
     def __str__(self):
         strings = []
-        strings.append(
-            "_in_declarative_mode_:" + str(self._in_declarative_mode_)
-        )
+        strings.append("_in_to_static_mode_:" + str(self._in_to_static_mode_))
         strings.append(
             "_functional_dygraph_context_manager:"
             + str(self._functional_dygraph_context_manager)
@@ -528,9 +526,9 @@ def _dygraph_only_(func):
 
 def _non_static_only_(func):
     def __impl__(*args, **kwargs):
-        from .dygraph.base import in_declarative_mode
+        from .dygraph.base import in_to_static_mode
 
-        assert in_dygraph_mode() or in_declarative_mode(), (
+        assert in_dygraph_mode() or in_to_static_mode(), (
             "We only support '%s()' in dynamic graph mode, please call 'paddle.disable_static()' to enter dynamic graph mode."
             % func.__name__
         )
@@ -2371,9 +2369,9 @@ class Variable(metaclass=VariableMetaClass):
         return _getitem_static(self, item)
 
     def __setitem__(self, item, value):
-        from .dygraph.base import in_declarative_mode
+        from .dygraph.base import in_to_static_mode
 
-        if in_declarative_mode():
+        if in_to_static_mode():
             if is_compiled_with_xpu():
                 # (NOTE): Currently, there is no index_put_xpu kernel.
                 return _setitem_impl_(self, item, value)
@@ -4325,12 +4323,9 @@ class Block:
                 'while',
                 'while_grad',
             }
-            from .dygraph.base import in_declarative_mode
+            from .dygraph.base import in_to_static_mode
 
-            if (
-                in_declarative_mode()
-                and not _stride_in_no_check_dy2st_diff_mode
-            ):
+            if in_to_static_mode() and not _stride_in_no_check_dy2st_diff_mode:
                 check_if_to_static_diff_with_dygraph(
                     op_type, inplace_map, outputs
                 )
@@ -4347,7 +4342,7 @@ class Block:
                 )
 
             self.ops.append(op)
-            if in_declarative_mode():
+            if in_to_static_mode():
                 record_is_view_var(op_type, inputs, outputs)
 
         return op
@@ -7645,10 +7640,10 @@ def _get_var(name, program=None):
 
 @signature_safe_contextmanager
 def dygraph_guard_if_declarative():
-    from .dygraph.base import in_declarative_mode
+    from .dygraph.base import in_to_static_mode
     from .dygraph import Tracer
 
-    if in_declarative_mode():
+    if in_to_static_mode():
         # Under @paddle.jit.to_static decorator, we switch back dygraph mode temporarily.
         with _dygraph_guard(tracer=Tracer()):
             yield
diff --git a/python/paddle/base/layers/layer_function_generator.py b/python/paddle/base/layers/layer_function_generator.py
index 17cf2820f85d2235f2ccf2fd8f03e59cd68789bf..358c2de238de113052252d3aa23e658b1a530df5 100644
--- a/python/paddle/base/layers/layer_function_generator.py
+++ b/python/paddle/base/layers/layer_function_generator.py
@@ -333,10 +333,10 @@ def generate_inplace_fn(inplace_op_type):
                     inplace_op_type, origin_op_type
                 )
             )
-            from ..dygraph.base import in_declarative_mode
+            from ..dygraph.base import in_to_static_mode
 
             if (
-                in_declarative_mode()
+                in_to_static_mode()
                 and hasattr(x, "is_view_var")
                 and x.is_view_var
             ):
diff --git a/python/paddle/base/layers/math_op_patch.py b/python/paddle/base/layers/math_op_patch.py
index d2858430a438dc1603128633b5ad44c7b21dc78f..c5d3b5ec8aa4b549c4216ab91a4aa2000db27c32 100644
--- a/python/paddle/base/layers/math_op_patch.py
+++ b/python/paddle/base/layers/math_op_patch.py
@@ -18,7 +18,7 @@ import inspect
 from .. import core
 from ..framework import Variable, unique_name, static_only
 from .layer_function_generator import OpProtoHolder
-from paddle.base.dygraph.base import in_declarative_mode
+from paddle.base.dygraph.base import in_to_static_mode
 
 _supported_int_dtype_ = [
     core.VarDesc.VarType.BOOL,
@@ -302,7 +302,7 @@ def monkey_patch_variable():
 
         """
         if not isinstance(var, Variable):
-            if in_declarative_mode():
+            if in_to_static_mode():
                 """in dy2static mode, x may be tensorable values such as int, float, np.array"""
                 from paddle.tensor.creation import to_tensor
 
diff --git a/python/paddle/base/variable_index.py b/python/paddle/base/variable_index.py
index 2efe308df0b832c8a06c878d319b037ba562ddac..74478b8a071f41ad06b27f9c75f1058d3d7b06d3 100644
--- a/python/paddle/base/variable_index.py
+++ b/python/paddle/base/variable_index.py
@@ -1017,9 +1017,9 @@ def _setitem_static(x, indices, values):
 def get_tensor_with_basic_indexing(
     x, axes, starts, ends, steps, decrease_axes, none_axes, use_strided_slice
 ):
-    from .dygraph.base import in_declarative_mode
+    from .dygraph.base import in_to_static_mode
 
-    if in_declarative_mode() and hasattr(x, "is_view_var"):
+    if in_to_static_mode() and hasattr(x, "is_view_var"):
         x.is_view_var = True
 
     if len(axes) == 0:
@@ -1111,7 +1111,7 @@ def get_tensor_with_basic_indexing(
 
         out = paddle.unsqueeze(out, axis=none_axes)
 
-    if in_declarative_mode() and hasattr(out, "is_view_var"):
+    if in_to_static_mode() and hasattr(out, "is_view_var"):
         out.is_view_var = True
     return out
 
diff --git a/python/paddle/jit/dy2static/convert_operators.py b/python/paddle/jit/dy2static/convert_operators.py
index 535c3713100e2c9aa73fe64f8fe51b9e1718244a..79e9b8489658c53ac7a6719238f34fb3c7b9d7c2 100644
--- a/python/paddle/jit/dy2static/convert_operators.py
+++ b/python/paddle/jit/dy2static/convert_operators.py
@@ -16,7 +16,7 @@ import re
 
 import paddle
 from paddle.base.data_feeder import convert_dtype
-from paddle.base.dygraph.base import _convert_into_variable, in_declarative_mode
+from paddle.base.dygraph.base import _convert_into_variable, in_to_static_mode
 from paddle.base.framework import Variable, core, default_main_program
 
 from .utils import (
@@ -38,14 +38,14 @@ def convert_attr(x, attr):
 
 
 def convert_load(x):
-    if in_declarative_mode() and isinstance(x, paddle.base.core.eager.Tensor):
+    if in_to_static_mode() and isinstance(x, paddle.base.core.eager.Tensor):
         """
         TODO:(@xiongkun) may run convert_load in dygraph mode, which should be fixed.
         """
         return _convert_into_variable(x)
 
     # get the new output of the var
-    if in_declarative_mode() and isinstance(x, Variable):
+    if in_to_static_mode() and isinstance(x, Variable):
         cur_block = default_main_program().current_block()
 
         from paddle.jit.dy2static.program_translator import ProgramTranslator
diff --git a/python/paddle/jit/dy2static/program_translator.py b/python/paddle/jit/dy2static/program_translator.py
index 48c9889cd150774755874653a1635c9279df4422..55fc6d55d0e28489e91b3ea6bf235b7784e2522c 100644
--- a/python/paddle/jit/dy2static/program_translator.py
+++ b/python/paddle/jit/dy2static/program_translator.py
@@ -23,7 +23,7 @@ import weakref
 from paddle.base import core, framework
 from paddle.base.data_feeder import check_type
 from paddle.base.dygraph.base import (
-    _switch_declarative_mode_guard_,
+    _to_static_mode_guard_,
     param_guard,
     switch_to_static_graph,
 )
@@ -1192,9 +1192,9 @@ class ConcreteProgram:
         new_name_generator = UniqueNameGenerator()
 
         with framework.program_guard(main_program, startup_program):
-            with _switch_declarative_mode_guard_(
-                is_declarative=True
-            ), UniqueNameGuard(new_name_generator):
+            with _to_static_mode_guard_(is_to_static=True), UniqueNameGuard(
+                new_name_generator
+            ):
                 # 1. Adds `paddle.static.data` layers for input if needed
                 static_inputs = func_spec.to_static_inputs_with_spec(
                     input_spec, main_program
diff --git a/python/paddle/nn/layer/layers.py b/python/paddle/nn/layer/layers.py
index 8e8c06ea2df49778352ce5d8fc6a1db49ef787a2..c80bfc4b39fb117a25e2fd0ed2b52d066725a765 100644
--- a/python/paddle/nn/layer/layers.py
+++ b/python/paddle/nn/layer/layers.py
@@ -26,9 +26,10 @@ from paddle import nn, profiler
 from paddle.base import core, framework, unique_name
 from paddle.base.core import VarDesc
 from paddle.base.dygraph import no_grad
+from paddle.base.dygraph.base import in_declarative_mode  # noqa F401
 from paddle.base.dygraph.base import (
     _convert_into_variable,
-    in_declarative_mode,
+    in_to_static_mode,
     program_desc_tracing_guard,
 )
 from paddle.base.dygraph_utils import _append_activation_in_dygraph
@@ -1336,7 +1337,7 @@ class Layer:
 
     def __call__(self, *inputs, **kwargs):
         if (
-            (not in_declarative_mode())
+            (not in_to_static_mode())
             and (not self._forward_pre_hooks)
             and (not self._forward_post_hooks)
             and (not self._built)
@@ -1561,7 +1562,7 @@ class Layer:
         if '_parameters' in self.__dict__:
             _parameters = self.__dict__['_parameters']
             if name in self._parameters:
-                if in_declarative_mode():
+                if in_to_static_mode():
                     return _convert_into_variable(self._parameters[name])
                 return self._parameters[name]
         if '_sub_layers' in self.__dict__:
@@ -1571,7 +1572,7 @@ class Layer:
         if '_buffers' in self.__dict__:
             _buffers = self.__dict__['_buffers']
             if name in _buffers:
-                if in_declarative_mode():
+                if in_to_static_mode():
                     return _convert_into_variable(_buffers[name])
                 return _buffers[name]
         return object.__getattribute__(self, name)
@@ -1653,7 +1654,7 @@ class Layer:
                         # but should all non-Variable _buffers[name] be re-assign? We
                         # should consider it in the future. I current wrote this as
                         # conservative code.
-                        if in_declarative_mode() and _buffers[name] is None:
+                        if in_to_static_mode() and _buffers[name] is None:
                             raise RuntimeError(
                                 'In Dy2stat, self.{0} is a buffer and self.{0} is '
                                 'not allowed to be set to Variable when self.{0} is None.'.format(
diff --git a/python/paddle/optimizer/adam.py b/python/paddle/optimizer/adam.py
index 75a1415690445d3358eb05248c1ffda44a105fc7..7464e36e1cff60d048064a4c8f17f5cb71bcb389 100644
--- a/python/paddle/optimizer/adam.py
+++ b/python/paddle/optimizer/adam.py
@@ -419,7 +419,7 @@ class Adam(Optimizer):
                 >>> adam.step()
                 >>> adam.clear_grad()
         """
-        if paddle.base.dygraph.base.in_declarative_mode():
+        if paddle.base.dygraph.base.in_to_static_mode():
             self._declarative_step()
             return
 
diff --git a/python/paddle/optimizer/adamw.py b/python/paddle/optimizer/adamw.py
index 823358bc1a71714ec0187ffdf332f2d27b2c8826..6341676747a5e17648155c48a9f8633ab5a720be 100644
--- a/python/paddle/optimizer/adamw.py
+++ b/python/paddle/optimizer/adamw.py
@@ -557,7 +557,7 @@ class AdamW(Optimizer):
                 >>> opt.step()
                 >>> opt.clear_grad()
         """
-        if paddle.base.dygraph.base.in_declarative_mode():
+        if paddle.base.dygraph.base.in_to_static_mode():
             self._declarative_step()
             return
 
diff --git a/python/paddle/optimizer/optimizer.py b/python/paddle/optimizer/optimizer.py
index f95db125adb2a3cb478e9392063d0cd846a1dbf5..5870db63d67afd27757637dad9ee3d01cbe89f2e 100644
--- a/python/paddle/optimizer/optimizer.py
+++ b/python/paddle/optimizer/optimizer.py
@@ -1603,7 +1603,7 @@ class Optimizer:
                 >>> adam.step()
                 >>> adam.clear_grad()
         """
-        if paddle.base.dygraph.base.in_declarative_mode():
+        if paddle.base.dygraph.base.in_to_static_mode():
             self._declarative_step()
             return
 
diff --git a/python/paddle/utils/inplace_utils.py b/python/paddle/utils/inplace_utils.py
index ee5032d0657fe7ad72dafa1bafd17a095b8f7cea..306c3fba5bf64bbd967aa9210d2a7647e5f9ffa2 100644
--- a/python/paddle/utils/inplace_utils.py
+++ b/python/paddle/utils/inplace_utils.py
@@ -33,9 +33,9 @@ def _inplace_apis_in_dygraph_only_(func):
                     func.__name__, origin_api_name
                 )
             )
-            from ..base.dygraph.base import in_declarative_mode
+            from ..base.dygraph.base import in_to_static_mode
 
-            if in_declarative_mode():
+            if in_to_static_mode():
                 for arg in args:
                     if hasattr(arg, "is_view_var") and arg.is_view_var:
                         raise ValueError(
diff --git a/test/dygraph_to_static/test_break_continue.py b/test/dygraph_to_static/test_break_continue.py
index dc5e74ff8d1933152b989631831f3726c662b05b..6c6547d579577f0eb26e5581caf8418dd4ce401d 100644
--- a/test/dygraph_to_static/test_break_continue.py
+++ b/test/dygraph_to_static/test_break_continue.py
@@ -39,7 +39,7 @@ class TestDy2staticException(unittest.TestCase):
             with self.assertRaisesRegex(Dygraph2StaticException, self.error):
                 paddle.jit.enable_to_static(True)
                 self.assertTrue(to_static(self.dyfunc)(self.x))
-        paddle.base.dygraph.base.global_var._in_declarative_mode_ = False
+        paddle.base.dygraph.base.global_var._in_to_static_mode_ = False
         paddle.jit.enable_to_static(False)
 
 
diff --git a/test/dygraph_to_static/test_ifelse.py b/test/dygraph_to_static/test_ifelse.py
index 381ba5b8daef4c9cac7a967d4893f72203e670ce..6e2dc6f8ffe6dfb5160e43d7b4629a39223b3e99 100644
--- a/test/dygraph_to_static/test_ifelse.py
+++ b/test/dygraph_to_static/test_ifelse.py
@@ -68,7 +68,7 @@ class TestDy2staticException(unittest.TestCase):
             with self.assertRaisesRegex(Dygraph2StaticException, self.error):
                 paddle.jit.enable_to_static(True)
                 self.assertTrue(paddle.jit.to_static(self.dyfunc)(self.x))
-        paddle.base.dygraph.base.global_var._in_declarative_mode_ = False
+        paddle.base.dygraph.base.global_var._in_to_static_mode_ = False
         paddle.jit.enable_to_static(False)
 
 
@@ -468,12 +468,12 @@ class TestDy2StIfElseRetInt4(TestDy2StIfElseRetInt1):
         with self.assertRaises(Dygraph2StaticException):
             static_func = paddle.jit.to_static(self.dyfunc)
             out = static_func(self.x)
-        # Why need set `_in_declarative_mode_` here?
-        # In Dy2St we use `with _switch_declarative_mode_guard_()` to indicate
+        # Why need set `_in_to_static_mode_` here?
+        # In Dy2St we use `with _to_static_mode_guard_()` to indicate
         # that the code block is under @to_static, but in this UT
-        # an exception is thrown during Dy2St, making the `_in_declarative_mode_`
-        # a wrong value. So We need set `_in_declarative_mode_` to False manually.
-        paddle.base.dygraph.base.global_var._in_declarative_mode_ = False
+        # an exception is thrown during Dy2St, making the `_in_to_static_mode_`
+        # a wrong value. So We need set `_in_to_static_mode_` to False manually.
+        paddle.base.dygraph.base.global_var._in_to_static_mode_ = False
         paddle.jit.enable_to_static(False)