Abstract: Objective: To measure expressions of cytokines genes in peripheral blood lymphocyte of patients after renal transplantation, evaluate cyclosporine A effect, further verify the necessity of testing cyclosporine A concentration 2. Methods: By SYBR GreenⅠ PCR technique, we measured IL-2 and IFN-γ mRNA expressions of PBL from 20 cases of patients 7 days after renal transplantation, assessed immunosuppressive effect of cyclosporine A, contrasted the relation of C0 and C2 with cytokines inhibiting. Results: Corresponding to C2, IL-2 and IFN-γ mRNA/β-actin mRNA relative templates were 0.038± 0.006 和0.018±0.004 respectively,IL-2 and IFN-γ inhibiting rates were (72.42±3.95)%和(69.52±6.97)%. linear correlation of C2 with inhibiting rate of IL-2、IFN-γ mRNA expression was fine(P<0.01), but the one of C0 with them was bad (P>0.05). Conclusions: To measure IL-2 and IFN-γ mRNA expressions in PBLof patients after renal transplantation with SYBR GreenⅠ PCR technique is an effective method to evaluate cyclosporine A effect and immunosuppressive study, C2 is still an important index to judge biological availability of cyclosporine A.