Objective: To explore the changes of myocardial mitochondrial structure and function in mice with viral myocarditis

and to observe the interventional effects of high dosage vitamin C. Methods: The male Balb/c mice were randomly divided into three groups:coxsackie B3 virus(CVB3) infection group(IG)

CVB3 infection group with high dosage vitamine C treatment (IVG) and control group(CG). The morphology

membrane phospholipid

as well as activities of cytochrome oxidase(CCO) and succinate dehydrogenase(SDH) of myocardial mitochondria were studied by using transmission electron microscope

morphometry and enzyme cytochemical method respectivly. Results: As compared to CG

a large number of mitochondria of IG was damaged

the activities of CCO and SDH of mitochondria declined

the apparent mitochondrial membrane phospholipid deletion and localization change were observed ( P<0.05 ～0.01). All of these were improved significantly in IVG (P<0.05～0.01). Conclusion: The myocardial mitochondrial structure was damaged apparently and its funtions declined obviously in viral myocarditis.High dosage vitamin C can have effects against myocardial mitochondrial structure damage and function decline.