Objective:To investigate the effects and mechanism of myosin light polypeptide 4(MYL4) on injury caused by viral myocarditis in mice. Methods:The experimental animals were randomly divided into the viral myocarditis group (n = 30) and the control group (n = 10). The viral myocarditis models were achieved by infection with coxsackievirus B3(CVB3). The proteomics assay was performed to identify the different proteins involve in the pathogenesis of viral myocarditis. The expression and the role of one identified protein MYL4 were evaluated by Western blot and ELISA. Results:Six proteins were successfully identified by MS:MYL4, heat shock protein β1, isocitrate dehydrogenase subunit α mitochondrial precursor, voltage dependent anion-selective channel protein 2, proteasome subunit α type 1 and macrophage capping protein. The expression of MYL4 was higher in the heart tissue and serum of VMC mice (P < 0.01), and ELISA results showed that the expression of MYL4 was related to the severity of disease(r = 0.97,P < 0.00). Conclusion:The MYL4 expression of VMC was higher than that of the control group, and also could indicate the injury degree, which suggesting that MYL4 might be involved in the pathogenesis of VMC.