Abstract: Aim To study the effects of abnormal blood flow power on uptake, synthesis and efflux of cholesterol in human umbilical vein endothelial cells(HUVECs). To further explore the role of abnormal blood flow power and cholesterol me＜x＞tabolism in the formation of atherosclerosis. Methods When the cells grew well, a new culture solution containing LDL and ApoA-I was used, and a force was applied. The cells were randomly divided into stress group, wall pressure group, normal group and no stress group according to the force acting on the cells. They were cultured for 24 hours under the action of the respective forces. Collect cells and culture medium to be used. The LDL and cholesterol concentrations in the four groups of culture medium were detected by enzymatic method. The content of intracellular cholesterol and The cholesterol content of cell membrane were determined by HPLC. The mRNA and protein ex＜x＞pression levels of LDLR, HMG-CR and ABCA1 were detected by real-time quantitative RT-PCR and western blot respectively. Results compared with the no stress group, the content of LDL in the culture medium of the stress group was significantly decreased and the content of intracellular cholesterol was significantly increased. Moreover, the ex＜x＞pression of mRNA and protein of LDLR and HMG-CR was significantly increased. In the wall pressure group, the cholesterol content in the culture medium was significantly increased, the cholesterol content in the cell membrane was significantly decreased, and the ex＜x＞pression of ABCA1mRNA and protein was significantly increased. In the normal group, LDL was significantly decreased and cholesterol significantly increased in the culture medium, and the ex＜x＞pression of mRNA and protein of LDLR、HMG-CR and ABCA1 was significantly increased. Conclusions stress promotes the uptake of LDL and synthesis cholesterol by up-regulating the ex＜x＞pression of LDLR and HMG-CR mRNA and protein, and wall pressure promotes cholesterol efflux by up-regulating the ex＜x＞pression of ABCA1mRNA and protein. Abnormal blood flow power disturbs the cholesterol me＜x＞tabolism balance of vascular endothelial cells and causes AS.