Objective To investigate the effect of myoblast transplantation on duchenne muscular dystrophy (DMD) and to explore the method and feasibil ity of applying gene therapy to DMD. Methods Myoblast of C57/BL10 mice were cultured using multiple-step enzyme digestion method and differential velocity adherent technique. The morphology of the cells was observed with inverted phase contrast microscope. The cells at passage 4 were labeled with 5-BrdU. Twenty-four DMDmodel mice (mdx mice: aged 4-6 weeks, male, 13.8-24.6 g) were randomly divided into two groups (n=12 per group): group A, 1 × 106/mL labeled myoblast were injected via ven caudal is twice at an interval of 2 weeks; group B: 1 mL DMEM/F12 was injected in the same manner serving as a control group. The mice were killed 4 weeks after operation and the motor abil ity of the mice was detected by one-time exhaustive swimming before their death. HE staining and immunohistochemistry staining observation for 5-BrdU, desmin, and dystrophin (Dys) were preformed, and the imaging analysis was conducted. Results The primary myoblast could be sub-cultured 5-7 days after culture, providing stable passage and sufficient cells. The time of onetime exhaustive swimming was (60.72 ± 5.76) minutes in group A and (47.77 ± 5.40) minutes in group B, there was significant significance between two groups (P lt; 0.01). At 4 weeks after injection, HE staining showed that in group A, there were round and transparent-stained myocytes and the percentage of centrally nucleated fibers (CNF) was 67%; while in group B, there were uneven muscle fiber with such pathological changes as hypertrophia, atrophia, degeneration, and necrosis, and the percentage of CNF was above 80%. Immunohistochemistry staining revealed that the expression of 5-BrdU, desmin, and Dys was positive in group A; while in group B, those expressions were l ittle or negative. Image analysis result displayed that integral absorbency (IA) value of desmin was 489.70 ± 451.83 in group A and 71.15 ± 61.14 in group B (P lt; 0.05) and the ratio of positive area to thetotal vision area was 0.314 3 ± 0.197 3 in group A and 0.102 8 ± 0.062 8 in group B (P lt; 0.05); the Dys IA value was 5 424.64 ± 2 658.01 in group A and 902.12 ± 593.51 in group B (P gt; 0.05) and the ratio of positive area to the total vision area was 0.323 7 ± 0.117 7 in group A and 0.035 2 ± 0.032 9 in group B (P lt; 0.05). Conclusion Myoblast transplantation has certain therapeutic effect on DMD of mice.