Aim To explore the effect of acid fibroblast growth factor （aFGF） on the apoptosis in endothelial progenitor cells （EPCs） from human umbilical cord blood （HUCB）. Methods Mononuclearcells （MNCs） were isolated from HUCB in vitro by Ficoll density gradient centrifugation,then the cells were plated on fibronectin-coated culture dishes. Aftert 7 days,the attached cells were treated by aFGF with different concentrations （2,5,10 μg/L） for 24 hours. EPCs were characterized as adherent cells with double positive to DiI-acetylated low density lipoprotein （DiI-acLDL） uptake and lectin binding by direct fluorescent staining under a laser scanning confocal microscope. Flow cytometry was used to detect cell apoptpsis. The expressions of Bcl-2 mRNA and protein were detected respectively by reverse transcription polymerase chain reaction （RT-PCR） and Western Blot. Meanwhile,the attached cells in the group （5 μg/L aFGF group） of the most obvious effects on EPCs were cultured for 6,12,24,48 h respectively,accordingly,to explore the relationship between time and effect of 5 μg/L aFGF group. Results Compared with control group,aFGF can argument the number of EPCs and inhibit apoptosis of EPCs （P<0.05）. The increase and inhibition ratio of apoptosis reached the maximum at 24 h after administration of 5 μg/L aFGF （P<0.05）. Expression of Bcl-2 mRNA and protein of EPCs in aFGF group was higher than that in control group （P<0.05）. Conclusions The results of the present study define a novel mechanism of the action of aFGF aFGF can augment the number and inhibit apoptosis of EPCs from HUCB via up -regulating Bcl-2 expression.