Abstract: Objective This experiment is conducted to select the appropriate concentration and time of serum and colchicine to synchronize breast cancer MCF- 7 cells at G0/G1 and G2/M phases， respectively. Methods MCF-7 was treated with different serum concentration to induce cell at G0/G1 stage synchronization，and treated with colchicine reagents to induce cell at G2/M synchronization. Cell cycle distribution was analyzed by flow cytometry for 12，24，36 h. Results After 24 hours treated，in 1% serum concentration group，the percentage of MCF-7 at G0/G1 accounted for（72. 96 ± 0. 84）%；in 1. 0 μg /mL colchicine reagent group，the percentage of MCF-7 at G2/M stage was（73. 67 ± 1. 77）%. 36 hours after treatment，in experiment groups of 1% serum and the group of colchicine， cell apoptosis was induced. Conclusion In experimental groups，1% serum treating and 1. 0 μg/mL colchicine regents treating for 24 h can basically completed cell cycle synchronization at G0/G1 and G2/M phases，respectively.

Key words: serum starvation, cell cycle synchronization, colchicine regents, apoptosis, G0/G1, G2/M