Objective To investigate the effect and mechanism of Allicin on apoptosis of Human Umbilical Vein Endothelial Cells（HUVEC）induced by H2O2. Methods To establish a model of oxidative stress apoptosis of HUVEC induced by H2O2. MTT， RT-PCR and western-blot were used to detect the effects and mechanism of Allicin on the model. Results Allicin can decrease the apoptosis rate induced by H2O2 in HUVEC cells. The expression of eNOS gene was increased by allicin significantly， the cutting of PARP was impaired， the expression of pro-Caspase-3 was increased， and the expression of Bax was decreased. Conclusion Allicin has powerful protective effects on HUVEC cells from apoptosis.