Abstract： Objective To investigate the renal pathologic changes in both donors and transplant recipients with delayed graft function (DGF).Methods The clinical and laboratory data were retrospectively analyzed in 144 renal recipients with DGF.All the patients received renal biopsy,and donors' biopsy was performed on 131 recipients.The pathological changes were examined under the light microscopy (LM),immunofluorescence (IF) and electron microscopy (EM).Results (1) The incidence of DGF was 10.16%-7.48% during 1994 to 2005,and decreased to 5.35 % during 2006 to 2009.(2) Anuria occurred in 24 cases (16.67 %),oliguria in 24 (16.67%) and hypertension in 68 cases (47.22 %).The enlargement of transplanting kidney and the increased vascular resistance was detected in 79.67 % (98/123 cases) and 45.53 % (56/123 cases) respectively by ultrasound examination.(3) The level of serum creatinine was ranged from 451 to 707 μmol/L.The high level of urinary NAG enzyme was found in 102 cases (70.83 %),proteinuria in 79 recipients (54.86 %) and hematuria in 77 cases (53.47 %).(4) The acute rejection was observed in 66 cases (45.83 %),toxicity of CNI in 22 (15.28 %),IgA nephropathy in 18 (12.50 %),acute tubular necrosis in 8 (5.56 %),and recurrent FSGS in 2 cases (1.39 %).(5) In most recipients (66/109 cases,60.55 %)immunosuppressive regimen altered and renal replacement therapy was given.Conclusion The causes of DGF are complicated.The quality of donors' kidney and early histological changes of recipients are contributed to the development of DGF.It is necessary to perform renal biopsy not only in donors but also in recipients with DGF.And kidney biopsy in transplanted patients was also beneficial to the treatment.