Aim To elucidate the effect of adrenocoticoids on viral myocarditis. Methods Two hundreds male 4-week-old Balb/c mice were divided into five groups randomly, including normal control group, infected control group, group of infected mice with adrenocorticoids treatment at early stage, group of infected mice with adrenocorticoids treatment at middle stage, group of infected mice with adrenocorticoids treatment at late stage. Normal control group mice were inoculated intraperitoneally with Eagle’s medium 0.1 mL. Infected group were inoculated intraperitoneally of 10 7.5 TCID₅₀ Coxsackievirus B₃ at a dose of 0.1 mL per mouse. Five mice of each group were sacrificed on 3, 7, 10, 14, 21, 30, 40 and 50 days post-inoculation. Pathologic examination and ultrastructure of heart, virus titer in heart by plaque-forming assay, serum cardiac troponin I with chemiluminescence immunoassay were examined. Results The myocardial histopathological score of mice in each infected group on day 7 to 10 after infection were significantly higher than that in normal control group, but no significant difference in each infected group. On day 14 after infection, the myocardial histopathological score of mice with adrenocorticoids treatment at middle stage were significantly lower than that in other infected groups, and no myocardial lesions were noted 30 days later post-infection while cardiac lesions could be noted in other infected groups. Virus titer in group of infected mice with adrenocorticoids treatment at early stage was significantly higher than that of in other infected group. Cardiac troponin I values were significantly greater in infected group than that in normal control group. There was a positive correlation between the level of cardiac troponin I and the change of myocardial histopathological score. Cardiac troponin I values was much lower after adrenocorticoids therapy, especially in group of infected mice with adrenocorticoids treatment at middle stage. Conclusions Adrenocorticoids therapy ameliorated the severity of myocardial lesions in viral myocarditis, especially used in middle stage of the disease. Adrenocorticoids therapy reduced the inflammatory infiltration in myocardium, inhibited autoimmune response. Adrenocorticoids therapy reduced the level of serum cardiac troponin I in viral myocarditis.