To observe the effect of Yangxin Dingxi Capsule in treating arrhythmia and its influence on traditional Chinese medicine score and ventricular premature beats.Methods:A total of 107 cases of qi and yin deficiency patients with arrhythmias accompanying ventricular premature beats were randomly divided into an observation group(56 cases)and a control group(51 cases).The control group was given conventional antiarrhythmic treatment of Western Medicine,and the observation group was given Yangxin Dingji Capsule based on the conventional treatment.We observed the changes of the efficacy and TCM syndrome score and ventricular premature beat between the 2 groups.Results:1)The total effective rate of the observation group was 92.86%,which was significantly higher than that of the control group(82.35%).The difference was statistically significant(P<0.05); 2)the syndrome scores of chest tightness,palpitation,shortness of breath,fatigue,dizziness and dry mouth between the 2 groups had significant differences(P<0.05),there were statistically significant differences in the scores of symptoms between the 2 groups after treatment for 1 week and 1 month(P<0.05); 3)The frequency of ventricular premature beat between the 2 groups had significant differences(P<0.05).Comparing the frequency of premature ventricular contractions between the 2 groups of treatment for 1 week and 1 month,the difference was statistically different; 4)There were not statistical differences in adverse reaction between the 2 groups(P>0.05).Conclusion:Yangxin Dingji Capsule can improve the clinical efficacy of arrhythmia，and significantly improve the clinical symptoms and reduce the occurrence of ventricular premature beats.