diff --git a/python_module/megengine/_internal/dtype.py b/python_module/megengine/_internal/dtype.py
index 7d0eb61a9a111b19fa0c383ae4bb27fc10940c9e..6bb32f8634a32ae2e964f4f10b9817e5a7b7b42b 100644
--- a/python_module/megengine/_internal/dtype.py
+++ b/python_module/megengine/_internal/dtype.py
@@ -25,6 +25,9 @@ _metadata_dict = {
     "qint32": _QuantDtypeMetadata(
         "QuantizedS32", "int32", False, -(2 ** 31), 2 ** 31 - 1,
     ),
+    # NOTE: int2 is not supported for model dump yet
+    "quint2": _QuantDtypeMetadata(None, "uint8", True, 0, 3),
+    "qint2": _QuantDtypeMetadata(None, "int8", False, -2, 1),
 }
 
 
diff --git a/python_module/megengine/quantization/__init__.py b/python_module/megengine/quantization/__init__.py
index 82feced1cc3738598f6664f4079e23a6d4854f75..9c8a0e0da5f9f7c8609584653f68b1d3ab584c85 100644
--- a/python_module/megengine/quantization/__init__.py
+++ b/python_module/megengine/quantization/__init__.py
@@ -13,6 +13,7 @@ from .qconfig import (
     QConfig,
     calibration_qconfig,
     ema_fakequant_qconfig,
+    ema_lowbit_fakequant_qconfig,
     min_max_fakequant_qconfig,
     tqt_quant_qconfig,
 )
diff --git a/python_module/megengine/quantization/qconfig.py b/python_module/megengine/quantization/qconfig.py
index 4a7b75ecb12dbdb746823609de12f9977219a86f..6606c1a513be2cf3d1a766a7c044f550b6c8480d 100644
--- a/python_module/megengine/quantization/qconfig.py
+++ b/python_module/megengine/quantization/qconfig.py
@@ -92,6 +92,15 @@ ema_fakequant_qconfig = QConfig(
     act_fake_quant=partial(FakeQuantize, dtype="qint8", narrow_range=False),
 )
 
+ema_lowbit_fakequant_qconfig = QConfig(
+    weight_observer=partial(MinMaxObserver, dtype="qint4", narrow_range=False),
+    act_observer=partial(
+        ExponentialMovingAverageObserver, dtype="qint4", narrow_range=False
+    ),
+    weight_fake_quant=partial(FakeQuantize, dtype="qint4", narrow_range=False),
+    act_fake_quant=partial(FakeQuantize, dtype="qint4", narrow_range=False),
+)
+
 calibration_qconfig = QConfig(
     weight_observer=partial(MinMaxObserver, dtype="qint8", narrow_range=True),
     act_observer=partial(HistogramObserver, dtype="qint8", narrow_range=False),