Objective:To investigate in vivo and in vitro the role of PEDF on human lens epithelial cells biological behaviour regulation. Methods:In vivo study,aqueous PEDF concentration was detected by enzyme-linked immunosorbent assay(ELISA) in age-related cataract patients who underwent cataract phacoemulsification extraction surgery. The relationship of PEDF level was analyzed with LECs density on anterior lens capsular specimens and cataract types. In vitro study,PEDF was added in culture media of human lens epithelial cell line (HLE-B3). The growth activity of HLE-B3 was detected by Cell Counting Kit(CCK8). Flow cytometry with AnnexinV-FITC/7-AAD double staining method was used to detect the changes of cell cycle and apoptosis. Results:The mean aqueous PEDF concentration of 120 cataract cases was (156.2 ± 41.2)ng/ml. The central anterior subcapsular LEC density significantly decreased with aqueous PEDF level reducing(r = 0.556,P < 0.01),and the positive correlation remained after controlling the age factor(r = 0.387,P < 0.05). PEDF concentration in aqueous humor of cortical cataract was lower than that of nuclear sclerosis(P < 0.05). After adding PEDF in culture medium of HLE-B3 line,cell’s growth accelerated significantly(F = 187.33,P < 0.01),and apoptosis was significantly inhibited (the apoptosis rate fell from 13.50% to 2.08%,t = 7.90,P < 0.01),and the proliferative division activity increased (cell ratio in G2+S phase rose from 28.54% to 54.05%,t = 6.32,P < 0.01). Conclusion:In human eyes,PEDF may function as LEC cytotrophic factor to play the important biological effects of cell cycle regulation and anti-apoptosis,involved in maintenance of lenticular physiological state and cataract development.