Adipose tissue derived stem cells(ASCs) are multipotent cells capable of forming bone, cartilage, and other connective tissues. In this study we evaluated the effect of stem cells derived from adipose tissue on the muscle regeneration in partial removed skeletal muscle in rats. Male sprague-dawley rats were randomly divided into three groups: control, PBS-injected and ASCs-injected group. Stem cells were isolated from rat abdominal adipose tissue by collagenase digestion and ASCs labeled with superparamagnetic iron oxide(Feridex) were used. Muscle injury was subjected to rat bypartial removal of quadriceps femoris muscle. The labeled cells were directly injected into the muscle injured area after muscle injury an hour. After 2 weeks, histological analysis was performed using H&E staining and prussian blue staining. The muscle regeneration markers were examined by immunohistochemistry and RT-PCR. ASCs labeled with Feridex were detected by prussian blue staining in injured muscle area. Microscopical muscle regeneration and neovascularization were more increased in ASCs-injected group compared to PBS-injected group. The expression level of Pax7, MyoD and myogenin were more significantly increased in ASCs-injected group compared with the PBS-injected group. This preliminary observation shows that ASCs may be directly involved in the regeneration process of injured skeletal muscle; therefore the possibility of using ASCs as a stem cell therapy for muscle regeneration need to be further investigated for the purpose of clinical trials.