Aim To investigate the effect of lycopene in endothelial progenitor cells of human peripheral blood and its underlying molecular mechanism. Motheds The promotion survival effect of lycopene in different concentrations on endothelial progenitor cells was measured by thiazolyl blue(MTT) assay.Cell cycle was analyzed by flow cytometry.The expression levels of cyclin-dependent kinase 4(CDK4) and cyclin D1 were detected by reverse transcription polymerase chain reaction(RT-PCR) and real-time polymerase chain reaction(real-time PCR) and Western blot. Results The MTT assay showed that lycopen promoted survival effect on endothelial progenitor cells in a time and dose-dependent manner.Flow cytometry analysis revealed that G1 phase of endothelial progenitor cells was decreased after exposed to different concentrations of lycopene.The expression levels of CDK4 and cyclin D1 were increased significantly after treated with lycopene in a dose-dependent manner using RT-PCR,real-time PCR and Western blot. ConclusionThe promotion survival effect of lycopene in endothelial progenitor cells is related to G1 phrase reducing through increased expression levels of CDK4 and cyclin D1.