Abstract: Objective:To observe the effects of wenxinkeli on the arrhythmia of acute coronary syndrome(ACS) and angiotensin Ⅱ(AngⅡ).Methods:Fifty-five cases with ACS were randomly divided into control group(27 cases) which were treated with conventional medication and treatment group(28 cases) which were treated with conventional medication added to wenxinkeli by oral.The arrhythmia and plasma AngⅡof two groups were observed.Results:The arrhythmia of the treatment group were less than that of the control group(P0.05).The plasma concentration of AngⅡ and N-terminal prohormone of brain natriuretic peptide of two groups had no significant difference at 2 weeks after treatment with wenxinkeli(P0.05).The mortality of two groups had no obviouse difference after 6 months(P0.05).Conclusions:Wenxinkeli can treat arrhythmia,prevent serious arrhythmia and no side-effects in the patients with ACS,which has no influence on plasma AngⅡafter 2 weeks.