Abstract: One of the most important causes of the atherosclerosis is reactive oxygen species (ROS) to induce lipide overoxidation, which leads to endothelial cells dysfunction and vascular smooth muscle cells (VSMCs) abnormal proliferation. Recent investigations demonstrated that polyphenon has prevention effect in the treatment of atherosclerosis or other vascular diseases. In this paper, endothelial cells (ECs), VSMCs and HL-60 cell (as the abnormal cell model) were used to investigate the effects of green tea catechins on the proliferation. Furthermore, the clearance ability of ROS by catechins was detected by hypoxanthine-xanthineoxidase chemiluminescence method. It was found that the green tea catechins could lightly increase ECs proliferation at the concentration of 1 μg/mL, and green tea catechins of 1 and 3 μg/mL have no obvious effect on VSMCs proliferation. However, green tea catechins of 10 μg/mL significantly inhibited VSMCs proliferation. For HL-60 cells, the cell viability was presented in a dose-dependent manner. Similarly, the ROS clearance ability was also related to the dosage of green tea catechins.