Aim To explore the effect of monocyte chemoattractant protein-1 (MCP-1) in viral myocarditis(VMC) and the change of MCP-1 after astragaloside intervention. Methods Fifty-five male 4-week-old Balb/c mice were randomly divided into 4 groups:normal control group (n=10),model control group (n=15),low-dose intervention group (n=15) and high-dose intervention group (n=15). Mice in the latter three groups were inoculated with 0.1 mL coxsackie B3 virus intraperitoneally. Then,mice in low-dose and high-dose intervention groups were treated with 0.01 g/L and 0.09 g/L astragaloside solution,respectively. Mice in normal control group and model control group were treated with carboxymethycellulose solution. All mice were killed on day 15. Histological cross sections of heart were stained with hematoxylin-eosin and myocardial histopathologic scores were counted under optical microscope. The expression levels of myocardial MCP-1 mRNA and protein were detected by RT-PCR and immunohistochemistry. Results The mortality was 0,46.7%,40.0% and 13.3% in normal control group,model control group,low-dose intervention group and high-dose intervention group respectively. Compared with model control group and low-dose intervention group,the mortality was significantly lower in high-dose intervention group (P><0.05). The expression levels of MCP-1 mRNA and protein for model control group were markedly higher than those of normal control group(P><0.01). However,the expression cevels of MCP-1 mRNA and protein and myocardial histopathologic scores in high-dose intervention group were decreased markedly compared with model control group and low-dose intervention group (P><0.05 or 0.01). Conclusion MCP-1 may participate in the pathogenesis of VMC. The therapeutic effect of Astragaloside on VMC is associated with inhibiting MCP-1 expression.