Objective: A BALB/c mice model of cytomegalovirus-induced myocarditis was established. Methods: Twentyfive inbred female BALB/c mice free of murine cytomegalovirus(MCMV) infection (5 weeks old, 16-18 g), were infected with 1 x 104PFU MCMV by the intraperitoneal (i. p. ) administration. All experimental mice were sacrificed on day 3, 5, 7, 10, and 14 after i. p. administration. The hearts were removed under aseptic conditions, and were transected along the midline. Aliquots of hearts were handled with Bouin' s fixative for histological examination. Residual hearts were immediately frozen in liquid nitrogen and stored at - 80℃ until MCMV titre was determined by a plaque assay. Seurm cTnI level was assayed by ELISA. Results: MCMV in the heart was at extremely low level on day 3 after i. p. administration, reached to the peak on day 7-10, and then ran down. A mixed cellular infiltrate composed of polymorphonuclear neutrophils and mononuclear lymphocytes was observed on day 3, reaching to the peak on day 7-10 after MCMV infection, and was maintained for at least 3-4 months later. Seurm cTnI levels were elevated on day 3 after i.p. administration, reaching to the peak it day7-10. Conclusion: The BALB/c mice model for cytomegalovirus-induced myocarditis was successfully established, that might make it possible to screen antiviral drugs for treating viral myocarditis and to investigate and evaluate the pathogenesis and prognosis of this disease.