OBJECTIVE： To improve medication compliance of patients with nonvalvular atrial fibrillation （NVAF） to warfarin and its influential factors， and to provide reference for guaranteeing the safety and effectiveness of therapy. METHODS： A questionnaire survey was conducted among NVAF patients receiving warfarin anticoagulation in our hospital， MMAS-8 and WRKS were adopted to evaluate medication compliance of patients to warfarin and the understanding of patients to the knowledge of anticoagulation treatment. Related influential factors for medication compliance of patients to warfarin were investigated by χ2 test， t test and Logistic multiple regression analysis. RESULTS： Totally 129 questionnaires were sent out， and 112 were effectively received with effective recovery of 86.82％. The mean score of MMAS was （6.54±1.61）， and 42.86％ patients had good medication compliance. The mean score of WRKS was （7.95±1.65）； that of patients with good medication compliance was （9.31±0.83）， and that of patients with poor medication compliance was （6.92±1.34）. Single factor analysis showed that there was statistical significance in gender， age， occupation， educational level， the number of compliance， WRKS score between patients with good medication compliance and those with poor medication compliance （P＜0.05）. Multivariate Logistic regression analysis showed that WRKS score， gender， educational level and the number of compliance were significantly correlated with medication compliance （P＜0.05）. CONCLUSIONS： Poor medication compliance of NVAF patients to warfarin is related to multiple influential factors. The knowledge of warfarin anticoagulation is an important factor.