Abstract: Objective: To determine the relation between transforming growth factor beta1（TGF-beta1）in allograft and chronic allograft nephropathy （CAN）. Methods: Urine TGF-beta1 relative concentration（divided by urine creatinine）was tested in 152 recipients whose renal function were normal between August 1, 2000 and February 28, 2001. 25 cases with higher urine TGF-beta1 relative concentrations formed group A,and other 25 cases with lower urine TGF-beta1 formed group B. In both groups biopsies were carried out in 15 cases and 12 cases respectively. TGF-beta1mRNA and TGF-beta1 in the biopsis were tested by RT-PCR and immunofluorescence.Blood TGF-beta1 concentrations in the two groups were also tested. Three years later, the renal function was compared between the two groups. Biopsies were carried out in renal recipients whose creatinine is higher than normal.Results: Blood TGF-beta1 concentrations in the two groups were not different significantly; 3 years after transplantation, there was more loss of renal function and more number of chronic allograft nephropathy （CAN） cases in group A than group B. Expression of TGF-beta1mRNA and TGF-beta1 in the allografts is more in group A than in group B. The differences in the two groups were significant.Conclusions: The findings suggest higher expression of TGF-beta1 in the allografts is associated with lower long-term survival rate of kidney graft. The level of urine TGF-beta1 after renal transplantation can predict long-term renal function.