Objective To analyze warfarin anticoagulation therapy for patients after heart valve replacement,and to explore an optimal intensity of warfarin anticoagulation.Methods The administration method,international normalized ratio (INR) monitoring of 265 patients who received warfarin anticoagulation therapy after heart valve replacement were analyzed retrospectively.The patients were divided into three groups according to different valve prostheses:aortic valve replacement (AVR) group (37 cases),mitral valve replacement (MVR) group (165 cases) and double valve replacement (DVR) group (63 cases).Each group was divided into two subgroups according to their INR levels (INR 1.5-2.0,INR 2.1-2.5).The occurrence of bleeding and thromboembolic events in these subgroups were compared.Results A total of 265 cases were visited,and followed up for 4 months to 6 years.The dose of warfarin was 0.625-7.500 (2.5 ± 1.4) mg/d.The incidence of anticoagulation adverse events was 23 cases.The incidence of bleeding events was 6.79％ (18/265),which was higher than that of thromboembolic events (1.89％,5/265),and there was significant difference (P ＜ 0.05).Four cases of the hemiplegia sequelae occurred and 2 cases died.The incidence of bleeing events in patients with INR1.5-2.0 in AVR group,MVR group and DVR group were 0 (0/20),3.57％ (3/84),2.70％ (1/37),in patients with INR 2.1-2.5 were 1/17,11.11％ (9/81),15.38％ (4/26),and there were significant differences (P ＜ 0.05).There were no significant differences in the incidence of thromboembolic events between INR 1.5-2.0 and INR 2.1-2.5 in AVR group,MVR group and DVR group (P ＞ 0.05).Conclusions After heart valve replacement,the anticoagulation therapy with warfarin is effective and safe to maintain the low intensity anticoagulation (INR1.5-2.0).AVR and MVR/DVR may benefit from a treatment strategy with levels ranging from 1.5-1.8 and 1.8-2.0,and the anticoagulation therapy of individuation should be formulated according to different conditions.