Background Gastric submucosal tumors (SMTs) diagnosis relie on pathologic diagnosis including immunohistochemical (ICH).Endoscopic ultrasound guided needle biopsy (EUS FNA) is one of the effective methods to obtain SMTs pathological specimens, but the histopathologic diagnosis rate is low, especially the small SMTs.Regardless of the larger or smaller SMTs, mucosal incision biopsy (MCB) technology can quickly obtain large pieces of biopsy under direct view.The purpose of this study was to compare the histopathologic diagnostic including ICH efficiency of MCB and EUS-FNA in gastric SMTs .Methods Between September 2017 to December 2019 in the Department of Gastroenterology,Shanghai Jinshan Branch of the Sixth People"s Hospital,40 patients with SMTs were selected for diagnostic examination.According to the Japanese GIST Therapeutic Guidelines, EUS-FNA was used as the preferred diagnostic method in principle. If the histopathological diagnosis of EUS-FNA sampling was insufficient or the technique was not appropriate because of tumor size or location, MCB supplementary sampling was adopted.The clinicopathological data of these patients were retrospectively analyzed to compare the diagnostic efficacy and safety of two groups .Results All 40 patients witn SMTs were diagnosed by MCB or/and EUS-FNA.Among them, 19 cases of SMT were diagnosed by MCB alone, 24 cases were diagnosed by EUS-FNA, and the other 7 cases were diagnosed by EUS-FNA combined witn MCB. There was no significant difference in operation time between MCB and EUS-FNA. The overall pathological diagnosis accuracy was similar between the two groups. However, there was a significant difference in ICH diagnosis rate, 93% VS 59%(p=0.03).Conclusion As an effective diagnostic method for gastric SMTs,MCB has better ICH diagnostic rate than EUS-FNA .