Objective To explore the change of cellular immune function in renal cancer patients adopting thymopetidum (TP-5) combined with cytokine-induced killer cells (CIK) in peroperative period,and evaluate its curative effect.Methods Forty-one cases of Ⅰ-Ⅲ stage renal cancer patients adopting CIK treatment postoperatively were enrolled in this study for retrospective analysis.According to applicating condition of TP-5,the patients were divided into two groups:16 cases of combination group (TP-5+CIK) and 25 cases of CIK group.The patients in combination group were given TP-5 intramscular injection everyday from preoperative 1 d to postoperative 3 weeks,once a day.Peripheral blood mononuclear cell was collected in the patients of two groups,which was cultivated for 2 weeks and then transfused.Fasting peripheral blood 1 week (before collected peripheral blood mononuclear cell),3 weeks (before CIK retransfusion),4 weeks(after CIK retransfusion for 1 week) and 5 weeks(after CIK retransfusion for 2 weeks) after operation were examined,the peripheral blood T cell subgroups (CD3+,CD4+,CD8+) and nature killer cell (NK cell) levels were detected using flow cytometry.Results At 1 week and 3 weeks (before CIK) after operation,the levels of CD3+,CD4+/CD8+ and NK cell in combination group were significantly higher than those in CIK group:1 week after operation:0.542 ± 0.063 vs.0.491 ± 0.054,0.94 ± 0.09 vs.0.90 ± 0.12,0.247 ± 0.025 vs.0.223 ± 0.033;3weeks after operation:0.641 ±0.058 vs.0.587 ±0.062,1.71 ±0.13 vs.1.02 ±0.07,0.319 ±0.038 vs.0.264 ± 0.047).There were significantly differences (P＜ 0.05).At 4 weeks after operation,the levels of CD3+,CD4+/CD8+ and NK cell in combination group were significantly higher than those in CIK group:0.698 ± 0.041vs.0.649 ± 0.050,2.01 ± 0.11 vs.1.64 ± 0.09,0.331 ± 0.029 vs.0.289 ± 0.034.There were significantly differences (P ＜ 0.05).At 5 weeks after operation,the levels of CD3+,CD4+/CD8+ and NK cell in two grotups were no significant difference (P ＞ 0.05).At 4 and 5 weeks after operation,the levels of CD3+,CD4+/CD8+ and NK cell in two groups were significantly higher than those of 3 weeks after operation (P ＜ 0.05).None of patients occurred acratia,hyperpyrexia,shivering and so on.Conclusions The application of TP-5 treatment in peroperative period can promote the recovery of cellular immune function,which has synergistic effect with CIK.The value of TP-5 is worthy of promotion.