Objective:To observe the autophagy of melanoma cell induced by rapamycin and explore the possible mechanism. Methods: M14 cells were cultured in vitro in the presence of rapamycin at three concentrations(10,50,100 nmol/L) for 24 hours. MDC fluorescent staining was used to detect autophagic vesicles. Immunocytochemistry was used to detect the expression of autophagy protein LC3B. Autophagosome was observed under transmission electronic microscopy. The expression levels of apoptosis-related protein Bcl-2 and Bax were measured by Western blot. Changes of mitochondrial membrane potential were examined by Rhodamine 123 dye and flow cytometry. The effects of rapamycin on proliferation of M14 cells were assessed using the MTT assay. Results: After rapamycin treatment,autophagy was induced in M14 cells as detected by MDC staining. The expression of LC3B increased. The intensity of autophagy was correlated with the concentration of rapamycin. Independent double membranes,swelling mitochondrias,autophagosomes and autolysosomes were observed in rapamycin-treated M14 cells under transmission electronic microscopy. Western blot revealed an upregulated expression of Bcl-2 and downregulated expression of Bax. Rapamycin at the concentrations of 10 to 100 nmol/L could markedly reduce the mitochondrial membrane potential compared with the control group(P < 0.05),and inhibit the proliferation of M14 cells in a dose-dependent manner. The growth inhibition was significantly higher than that of the control group(P < 0.01). Conclusion: Rapamycin at the concentrations of 10 to 100 nmol/L could induce autophagy in melanoma cells,and inhibit the growth of melanoma cells. The mechanism may be associated with the expression level of protein Bcl-2 and Bax.