Abstract: Objective　To explore the relationship of magnetic resonance imaging (MRI) performance in juvenile dermatomyositis (JDM) with clinical characteristics, especially serum muscle enzyme abnormalities. Methods　The images of 50 cases of JDM were reviewed, and the affected skin, subcutaneous connective tissue, muscle fascia and muscle were evaluated. The range of muscle edema under MRI images was categorized into 1-3 grades from mild to complete involvement. By comparing the MRI classification with muscle enzyme, we aim to reveal the linkage between the degree of muscle damage and the levels of muscle enzymes. The sequence of MRI examination of the thigh included rapid spin echo sequence FSE T1W, and the fat suppression sequence STIR in both coronary and axial position. Results　In the 50 cases of dermatomyositis, there were 49 cases of muscle edema, 28 cases of myofasciitis, 9 cases of subcutaneous connective tissue inflammation, and 4 cases of thickening skin. Of 49 cases of muscle edema, there are 16 cases in grade 1, 24 in grade 2 and 9 in grade 3. The median value of all muscle enzyme in the grade 2 group was higher than that in the other two groups, and the value of AST was statistically significant, P<0.05. Conclusions　The detection rate of JDM using MRI is high, which can help judge the severity and range of involvement. The MRI findings of JDM mainly demonstrated muscle edema, mostly moderate degree, followed by muscular fasciitis.