Objective:Postpolypectomy bleeding(PPB) is the most frequent complication after colonoscopic polypectomy.The aim of this study was to identify the risk factors for post-polypectomy bleeding after endoscopic mucosal resection (EMR) Methods: We retrospectively reviewed the clinical data of 111 patients who experienced postpolypectomy bleeding (PPB) after EMR with 176 patients who did not. Patient-related and polyp-related variables were evaluated as potential PPB factors.Results: Univariate logistic regression analysis showed gender (male,p=0.008), numbers of polyps removed(≥3 polyps,p=0.001), polyp’ daimeter (≥10 mm,p=0.000), location(right colon,p= 0.036), use of antithrombotic drug (p=0.015) were significantly correlated with PPB.Performed In the aboved factors,hypertension(P<0.1) and pathological type (adenoma,P<0.1),multivariate logistic regression analysis showed that only gender (male) ,polyps’ diameter(≥10 mm) and numbers of polyps removed(≥3 polyps) were significantly associated with PPB after EMR.Conclusions:Gender (male) ,polyps’ diameter(≥10mm) and polyp number(≥3 polyps) are significantly associated with PPB after EMR,we should pay more attention on these factors to prevent post-polypectomy bleeding.