Objective：The effects of palmitic acid (PA) on the differentiation and function of mouse skeletal muscle stem cells was detected for the new medicine-sarcopenia.Methods：One hundred μmol/L PA was added to skeletal muscle stem cells.The morphological changes of the cultured cells were observed，the myosin heavy chains(MyHC) of the culture cells was determined using immunocytochemistry and the expression of the gene was determined by real time PCR. Oxygen consumption rates (OCR) was measured by XFe24 extra cellular flux analyzer. Levels of mitochondrial fusion and fission marks such as Mfn1，Opa1，Drp1，Fis1 were measured. Results：When the cells treated with PA，fluorescent expression of MyHC was decreased and the fusion rate of myotube also reduced. The oxygen consumption rate (OCR) in the presence of PA was decreased(P＜0.05). The fusion mark was not significantly changed，but mitochondrial fusion index(Mfn1-to-Drp1ratio) was significantly increased. Conclusion：The results showed that PA inhibited the differentiation of skeletal muscle stem cells and OCR of mitochondria. The effects of PA on myogenesis were carried out through decreasing the fusion of mitochondria.