BACKGROUND:In recent years,pentoxifyIline has been found to have a wide range of anti-fibrosis capacity However,there are few studies explore the suppress effect of pentoxifyIline on fibroblasts in human keloid.and the maximum inhibitory concentration remains poorly understood.OBJECTIVE:To study the effect of pentoxifyIline on proliferation activity of human keloid fibroblasts and to select the maximum inhibitory concentrationMETHODS:Human keloid fibroblasts were used as original cells,passaged till the 5~(th) to the 8~(th) generations.and then divided into the experimental and control groups.PentoxifyIline with concentrations of 0.1,0.25,0.5,1.0,2.0 and 3.0 g/L were added to the experimental group.The effects of different concentrations of pentoxifylline on proliferation of keloid fibroblasts were detected by MTT chromometry.RESULT AND CONCLUSION:Compared with the control group,the inhibitory effect of pentoxifylline on the proliferation of keloid fibroblasts was more evident in the experimental group(P＜0.05)The inhibition rates of pentoxifylline on proliferation of keloid fibroblasts showed apparently time-and dose-effect relationships within the concentration of 0.1-2.0 g/L.which presented a greatest level at 96 hours after culture.The maximum inhibitory rate was 53 37%,and the concentration was 2.0 g/L in the experimental group.Consequently,pentoxifyIline plays a notable inhibitory role in the proliferation of human keloid fibroblasts with concentration of 2.0 g/L at 96 hours after culture.