To investigate the effect of mouse melanoma cell line B16F10-derived conditioned medium on the apoptosis of B16F10 cells.B16F10 cells were cultured in high-glucose DMEM in the presence of 10% fetal bovine serum, and upon cell confluence, the growth medium was replaced with serum-free high-glucose DMEM. After 8 h, the medium was collected and infiltrated to serve as the conditioned medium. B16F10 cells cultured in normal growth medium or the conditioned medium were exposed to 10 mmol/L sodium L-ascorbate, and the cell apoptosis was analyzed. The ingredients in the conditioned medium with relative molecular mass less or more than 5 000 were extracted to assess their effect on sodium L-ascorbate-induced cell apoptosis.The conditioned medium for B16F10 cells significantly inhibited cell apoptosis induced by sodium L-ascorbate, and the effective ingredients in the medium showed a relative molecular mass below 5,000.Mouse melanoma cell line B16F10-derived conditioned medium can suppress sodium L-ascorbate- induced apoptosis of B16F10 cells, and the ingredients with relative molecular mass less than 5 000 are responsible for this effect.