OBJECTIVE: To evaluate the efficacy and safety of Chinese medicinal shensongyangxin capsules in the treatment of paroxysmal atrial fibrillation. METHODS: From August 2007 to July 2008, Beijing Chaoyang Hospital conducted a multicenter study, select the eleven hospital's outpatient subjects, aged 18 to 75 years old, male or female, paroxysmal atrial fibrillation (at least one electrocardiogram diagnosis) seizure frequency ≥ 2 times/month, according to the ratio 1:1:1, subjects were randomly divided into three groups: a. shensongyangxin group, taking shensongyangxin capsule 4 + propafenone analogues 150 mg, 3 times a day; b. propafenone group, taking propafenone tablets 150 mg + 4 shensongyangxin analogues, 3 times a day; shensongyangxin capsule + propafenone group, taking shensongyangxin capsule 4 + propafenone 150 mg, 3 times a day. The treatment course is 8 weeks, with 3 times of follow-up. RESULTS: Total of 349 cases of paroxysmal atrial fibrillation, which 117 cases in shensongyangxin group, 115 cases in propafenone group; 117 cases in shensongyangxin + propafenone group. The baseline data analysis showed that there were no significantly difference (P > 0.05) among the three groups of atrial fibrillation seizure frequency, vital signs, general condition, medical history, 24-hour ambulatory ECG, 12-lead normal electrocardiogram, cardiac ultrasound and symptoms. The comparison before and after (8 weeks) treatment showed that the frequency (from 6 times/m to 2 times/m in each group, P < 0.01), number of cases [from 46 (43.3%) to 22 (20.8%), 43 (43.4%) to 25 (25.3%), and 40 (40.6%) to 31 (29.2%), respectively P < 0.01] and duration time of attack of atrial fibrillation (from 4 h to 0.5 h, 4 h to 0.5 h, and 4.25 h to 0.5 h, respectively P < 0.01) all decreased in three groups. No significant difference among the three groups comparing the overall effect (62.3%, 58.6%, and 58.5%, respectively, P > 0.05), while the efficacy of TCM symptoms in shensongyangxin group (80.2%) was better than that of propafenone group (67.7%) (P < 0.05). Safety evaluation showed that adverse reaction rate was 1.8% in shensongyangxin group, and 8.2% and 5.4% in propafenone group and shensongyangxin + propafenone group. CONCLUSION: Shensongyangxin capsules and propafenone have comparable efficacies in the treatment of PAF. The efficacy of TCM symptoms is better than propafenone. Shensongyangxin capsules have an excellent profile of safety.