Objective To evaluate the influence of Chinese patent medicine Banlangen Granules and Ganmao Qingre Granules on war‐farin anticogulation effect during the process for treating acute upper respiratory tract infection in the postoperative patients with mechanical valve replacement in order to provide the theoretical reference for clinical medication .Methods The patient receiving mitral valve replace‐ment ,aortic valve replacement or double‐valve replacement and long term postoperative oral warfarin anticoagulation treatment were select‐ed ,moreover the symptoms of complicating acute upper respiratory tract infection occurred .The patients were divided into 2 groups ,30 cases in each group .The group A adopted oral Banlangen Granules ,while the group B was treated by oral Ganmao Qingre Granules .The treat‐ment course was 3 d .The International Normalized Ratio (INR) in the two groups was monitored before medication ,at 72 h after medication and at 72 h after drug withdrawal .Complicating bleeding or embolism reaction was observed .The INR values at various time points were compared between the two groups and the INR values in each group were compared among 3 time points .Results The INR values in the Banlangen Granules group had statistical differences between 72 h and other two time points ,and the INR values at the same time point had statistical difference compared with the Ganmao Qingre Granules group (P<0 .05);the INR value in the Banlangen Granules group had no statistical difference between before medication and at 72 h after medication(P>0 .05) .Thirty cases had no complication occurrence .The Ganmao Qingre Granules group had no statistical difference among various time points (P>0 .05) ,thirty cases had no complication occur‐rence .Conclusion The warfarin combined with Banlangen Granules causes the INR value increase ,while warfarin combined with Ganmao Qingre Granules has no impact on the INR value ,therefore which suggests that the combination use of warfarin and Banlangen Granules should be cautious in clinic .