Here we firstly report that colostrum contains a high level of miR-30a. Using the miR-30a rich fraction extracted from colostrum, we successfully restrained the autophagy activity of HeLa cells induced by DDP, and promoted their apoptosis from 12.5% to 56.5% in 8 h post-treatment of DDP. By feeding the tumor-bearing mice undergoing DDP-chemotherapy with miR-30a- rich fraction from colostrum for 10 days, we reduced tumors size more effective than treating mice with DDP alone. In particular, the diameter of tumors was diminished to 4.5 mm after miR-30a-rich colostrum fraction administration during DDP chemotherapy, while the tumors treated with DDP only grown to 9.0 mm in diameter. In conclusion, the miR-30a-rich fraction of colostrum can sensitize the cancer cells to anti-cancer drugs, thus enhance the effect of chemotherapy drug on tumor treatment.