Objective To research the protective effect and mechanism of new compound Anti-Coxsackievirus B Myocarditis Capsule（ACMC）on cardiomyocytes infected by Coxsackievirus B3（CVB3）.Methods Four experimental concentrations were selected according to the maximum non-toxic concentrations（TC0）of ACMC and ribavirin.The well-grown H9C2cells were seeded in 96-well plates and divided into the ACMC group

ribavirin group

normal control group and virus control group.The effects of ACMC and ribavirin at different concentrations on cell proliferation

cell protection

direct anti-virus

anti-virus adsorption were observed by methyl thiazolyl tetrazolium（MTT）assay and indicated as OD values according to four-different dosing and virus-plus methods.Results The OD values at different concentrations in the ACMC and ribavirin groups were significantly higher than those in the model control group（P<0.05or P<0.01）.The OD value of cell proliferation at 0.390625mg/ml in the ACMC group was significantly higher than that at 0.1953125mg/ml and 0.09765625mg/ml in the ACMC group and at various concentrations in the ribavirin group respectively（P<0.05or P<0.01）.The OD value of cell protection at 0.78125mg/ml in the ACMC group was significantly higher than that at other concentrations in the ACMC group and at various concentrations in the ribavirin group respectively（P<0.05or P<0.01）.There was no significant difference between the ACMC group and ribavirin group in the OD values of direct anti-virus and anti-virus adsorption at various concentrations（P>0.05）.Conclusion ACMC can protect the cardiomyocytes through inhibiting the virus proliferation

protecting the cells

directly fighting the virus and preventing the virus adsorption

with best inhibition of virus proliferation at 0.390625 mg/ml and protection of cells at 0.78125mg/ml and superior to ribavirin.