Objective To quantitatively detect intragraft and peripheral blood monocyte cells (PBMCs) perforin mRNA,and analysis the relationship between acute rejection and perforin mRNA. Methods In the allograft group Wistar and male SD rats were used as donors and recipients.SD rats served as donors and recipients in the isograft group.The graft specimens were harvested 5 days postoperatively.They were examined histologically after sectioning and staining with hematoxylin and eosin,Masson’s trichrome, periodic acid-Schiff reagent and periodic acidsilver metheramine.And then the fluorescent quantitative PCR was employed to measure the intragraft and PBMCs expression level of perforin mRNA. Results The histological scores in allograft and isograft kidney samples were 2~5 (3.43?0.98) and 0~1 (0.71?0.49)(P