diff --git a/paddleocr.py b/paddleocr.py
index d52a88b3778ef3924566e0569a7f86d2da578eec..bc9b4e276c38eef127c3af615e69a6c61e41b928 100644
--- a/paddleocr.py
+++ b/paddleocr.py
@@ -47,7 +47,9 @@ SUPPORT_REC_MODEL = ['CRNN']
 BASE_DIR = os.path.expanduser("~/.paddleocr/")
 
 DEFAULT_OCR_MODEL_VERSION = 'PP-OCR'
+SUPPORT_OCR_MODEL_VERSION = ['PP-OCR', 'PP-OCRv2']
 DEFAULT_STRUCTURE_MODEL_VERSION = 'STRUCTURE'
+SUPPORT_STRUCTURE_MODEL_VERSION = ['STRUCTURE']
 MODEL_URLS = {
     'OCR': {
         'PP-OCRv2': {
@@ -190,7 +192,7 @@ def parse_args(mMain=True):
     parser.add_argument(
         "--ocr_version",
         type=str,
-        choices=['PP-OCR', 'PP-OCRv2'],
+        choices=SUPPORT_OCR_MODEL_VERSION,
         default='PP-OCRv2',
         help='OCR Model version, the current model support list is as follows: '
         '1. PP-OCRv2 Support Chinese detection and recognition model. '
@@ -199,7 +201,7 @@ def parse_args(mMain=True):
     parser.add_argument(
         "--structure_version",
         type=str,
-        choices=['STRUCTURE'],
+        choices=SUPPORT_STRUCTURE_MODEL_VERSION,
         default='STRUCTURE',
         help='Model version, the current model support list is as follows:'
         ' 1. STRUCTURE Support en table structure model.')
@@ -292,7 +294,7 @@ class PaddleOCR(predict_system.TextSystem):
         """
         params = parse_args(mMain=False)
         params.__dict__.update(**kwargs)
-        assert params.ocr_version in ['PP-OCR', 'PP-OCRv2']
+        assert params.ocr_version in SUPPORT_OCR_MODEL_VERSION, "ocr_version must in {}, but get {}".format(SUPPORT_OCR_MODEL_VERSION,params.ocr_version) 
         params.use_gpu = check_gpu(params.use_gpu)
 
         if not params.show_log:
@@ -395,7 +397,7 @@ class PPStructure(OCRSystem):
     def __init__(self, **kwargs):
         params = parse_args(mMain=False)
         params.__dict__.update(**kwargs)
-        assert params.structure_version in ['STRUCTURE']
+        assert params.structure_version in SUPPORT_STRUCTURE_MODEL_VERSION, "ocr_version must in {}, but get {}".format(SUPPORT_STRUCTURE_MODEL_VERSION,params.structure_version) 
         params.use_gpu = check_gpu(params.use_gpu)
 
         if not params.show_log: