Objective:To observe the therapeutic effectiveness a nd the safety coefficient of the thymopentin injection (TP-5) for chemotherapy of tumour patients with hypoimmunity. Methods:Thirty malignan t tumour patients were randomly divided into two groups:test group (chemotherapy combined with TP-5) and contrast group (chemotherapy combined with placebo). TP -5 and placebo were used while chemotherapy by intramuscular injection daily for 28 days. The blood routine examination、immunologic condition、liver function、 renal function and ECG were tested regularly. Results :The efficac y rate of the patients with TP-5 was 100%

but 26.7% (P＜0.05) w ith placebo. The injury of liver function、renal functin and ECG with TP-5 were not observed.Conclusion:TP-5 can improve the cell-immunologic func tion of tumour patients during chemotherapy.It was effective and safe in the clinical application.