Objective To observe the curative effects of action of adjuvant therapy with Wenban Tang（ 稳斑汤）on acute coronary syndrome（ ACS） patients with turbid phlegm and blood stasis syndrome and to study the possible mechanisms. Methods Totally 180 patients with ACS and turbid phlegm and blood stasis syndrome were chosen and randomly divided into the control group and the treatment group（ 90 cases in each group）; and 40 healthy volunteers were selected as the normal group. Both control group and treatment were given percutaneous coronary intervention and the routine western medicine. In addition to the above treatment

the treatment group also was given Wenban Tang once a day. Both groups were treated for one month. Methylation specific PCR method was used to detect plasma level of promoter methylation of thrombomodulin（ TM） gene in the normal group and the other two groups before and after treatment

and changes of Chinese medical syndrome scores and clinical curative effects in the control group and the treatment group were observed before and after treatment. Results TM gene promoter methylation rate was 45. 0%（ 81 /180） in both two patient groups

which was significantly higher than that in the normal group 17. 5%（ 7 /40）（ P < 0. 05）. After treatment

TM gene promoter methylation rate and Chinese medical syndrome scores in the treatment group and the control group were significantly lower than those in corresponding group before treatment

and those in the treatment group were significantly lower than those of the control group（ P <0. 05）. The effective cases accounted for 91. 11% of all cases in the treatment group

which was significantly higher than 77. 78% in the control group（ P < 0. 05）. Conclusion The treatment of western medicine with adjuvant Wenban Tang may significantly reduce Chinese medical syndrome scores of ACS patients with turbid phlegm and blood stasis syndrome. Clinical curative effects of western medicine with adjuvant Wenban Tang were superior to western medicine alone. And its mechanism may be related to reduce promoter methylation level of TM gene.