Abstract: Objective To study the relation between gastric mucosal lesion morphology under endoscope and its endoscopic biopsy accuracy. Methods Data about 266 patients undergone endoscopic submucosal dissection（ESD） for gastric mucosal lesions in our hospital from 2006 to 2011 were retrospectively analyzed.Difference was observed between gastric mucosal lesion and its endoscopic biopsy in 234 patients with 246 lesions diagnosed as gastric intraepithelial neoplasia（IEN） or early cancer out of the 266 patients. Results Endoscopic biopsy and postoperative pathology showed that the total accordance rate for IEN or cancer and types I,IIa,IIb,IIc and IIa+IIc gastric mucosal lesions was 94.3%（232/246）,91.7%（22/24）,90.9%（70/77）,94.4%（17/18）,95.7%（22/23） and 98.1%（102/104）,respectively.The complete accordance rate of endoscopic biopsy and postoperative pathology was 51.6%（127/246） for the lesions,especially for type IIa lesion 67.5%（52/77）.The grade of postoperative pathology was higher than that of endoscopic biopsy for the lesions 33.7%（83/246）,especially for type IIc lesion 52.2%（12/23）.The grade of pathology was lower than that of endoscopic biopsy for lesions 8.9%（22/246）,especially for type IIa lesions 13.0%（10/77）,and 5.7%（14/246） of the lesions were diagnosed as gastritis by postoperative pathology,including 8.3%（2/24） of type I lesions,9.1%（7/77） of type IIa lesions,5.6%（1/18） of type IIb lesions,4.3%（1/23） of type IIc lesions and 1.9%（2/104） of type IIa+IIc lesions. Conclusion It is possible to estimate the accuracy of endoscopic biopsy in diagnosis of gastric mucosal lesion according to its morphology.