Objective To observe the dynamic changes of interleukin-23 (IL-23)/interleukin-17 (IL-17) inflammatory axis expression in the myocardium of mice with viral myocarditis (VM) and further to explore its significance. Methods A total of 60 BALB/c mice were randomly divided into VMC group (n=50) and control group (n=10). Mice in VMC group were intraperito-neally inoculated with 0.1ml Eagle's solution containing coxsackievirus B3 (CVB3) to establish VM model and 10 mice were sacri-ficed each time at days 7, 14 and 28 after inoculation. Mice in control group were treated with 0.1ml Eagle's solution without CVB3 and all the 30 mice were killed on day 28 after inoculation. Myocardial histopathologic changes were detected with hema-toxylin and eosin (HE) staining and myocardial histopathological scores were calculated. The expression levels of myocardial IL-23/IL-17 mRNA and protein were determined by real-time quantitative PCR and immunohistochemistry, respectively. Serum IL-23 and IL-17 concentrations were examined using ELISA. Also, the relationship between serum IL-23 and IL-17 concentra-tions and myocardial histopathological scores was analyzed in VMC group. Results At days 7, 14 and 28 after inoculation, the myocardial histopathological scores, mRNA and protein expressions of myocardial IL-23/IL-17 and serum IL-23 and IL-17 con-centrations were significantly higher in VMC group than those in control group (P<0.01). Each of the above indicators reached its highest level on 7th day after inoculation (P<0.01) and then gradually decreased. There were significant differences among dif-ferent time points (P<0.05). Serum IL-23 and IL-17 concentrations showed significantly positive correlation with the myocardi-al histopathologic scores in VMC group, respectively (r=0.73 and 0.76, P<0.05). Conclusions IL-23/IL-17 inflammatory axis may play an important role in the process of VMC and is closely associated with the severity of VMC.