Objective To analyze the magnetic resonance imaging (MRI) findings and their relationship with biochemical markers of cardiac function in children with myocarditis. Methods The clinical data of 32 children with myocarditis admitted to our hospital from May 2016 to May 2018 were analyzed retrospectively. A total of 18 children with healthy physical examination were selected as control group. All children were given cardiac MRI, and the levels of serum cardiac troponin T (cTnT) and N-terminal pro-brain natriuretic peptide (pro-BNP) were detected. The clinical diagnostic results were used as controls to evaluate the diagnostic value of cardiac MRI on children with myocarditis. The detection rates of MRI in myocarditis children with different concentrations of cTnT and proBNP were compared. Results The sensitivity, specificity and accuracy of cardiac MRI in the diagnosis of myocarditis were 62.50%, 94.44% and 74.00%, and the Yodenindex was 0.57 and the kappa value was 0.502 with a general consistency with the clinical diagnosis results. The detection rates of cardiac MRI in children with cTnT>140ng/L and proBNP>614ng/L were higher than those in children with cTnT≦140ng/L and proBNP≦614ng/L (P<0.05). Conclusion MRI images of children with myocarditis are specific and children with elevated A and B indicators had higher detection rates..