·AIM:To detect the effect of CTGF on the apoptosis in the diabetic retina with small interfering RNAs(siRNA)targeting with CTGF.·METHODS:A total of 60 rats were divided into six groups including control group,diabetic 4,8,12,16 weeks group,and interference group.Diabetic rats were induced by STZ intra-peritoneal.At 4,8,12,16 weeks after diabetic setting up,retinas were obtained from control,diabetic rats and diabetic animals treated by intravitreal injection of CTGFsiRNA to suppress the expression of CTGF mRNA.Retinal cells apoptosis was detected by Tunnel staining and mRNA expression of CTGF was analyzed by RT-PCR.·RESULTS:The levels of CTGF and the apoptosis in the retinas of diabetic rats were significantly higher than those in the controls.Apoptosis occurred at 4 weeks after a diabetic model setting up,became serious with the diabetes developing,while CTGF elevated at 8 weeks.The cell apoptosis counts increased to 25.8cells/mm2 at 24 weeks of diabetes.SiRNA-mediated inhibition of CTGF mRNA resulted in a significant decrease in apoptosis.Significant correlations were found between CTGF and apoptosis in the retina.·CONCLUSION:These results suggest that CTGF might be involved in retinal cells apoptosis which is a characteristic of early diabetic retina.siRNA targeting CTGF seems to have the advantage of ameliorating retinal cells lost.·