Objective To explore the clinical value of the level of granzyme B and perforin mRNA in urine for the diagnosis of renal transplantation patients with delayed graft function (DGF). Methods Twenty-four cases of renal transplantation patients with DGF were included in this study. Seventy-three u-rine specimens were obtained from these patients who received graft biopsies. Among the 24 cases, ureteral obstruction occurred in 2 cases, vascular thrombosis in 1 case, acute CsA intoxication in 3 cases, acute tubu-lar necrosis (ATN) in 7 cases, ATN complicating borderline change in 2 cases, ATN complicating acute re-jection (AR) in 3 cases, AR in 6 cases. Total RNA was isolated from the urinary cells. Messenger RNA (mRNA) encoding the cytotoxic proteins perforin and granzyme B gene were measured with the quantitative polymerase-chain-reaction assay-(RT-PCR). SPSS13.0 software was used for data analysis. Levels of mRNA were log-transformed before analysis. Results The levels of perforin and granzyme B mRNA in u-rine among the ureteral obstruction group, vascular thrombosis group, acute CsA intoxication group and ATN group were very low. There was no significant difference among these groups (P>0.05). However,among the ATN complicating borderline change group 1.22, 0. 97 fg/μg, ATN complicating AR group (1.20±0.39), (1.07±0.30)fg/μg, and AR group(11.13±0. 33), (1.01±0.19)fg/μg, the levels were increased significantly(P<0.001). Conclusion Measurement of mRNA encoding the cytotoxic proteins perforin and granzyme B gene in urinary cells in renal transplantation patients with DGF could be helpful to etiological diagnosis of DGF, and might be used as an index for the appropriate management of the borderline change.