Abstract: Objective: To study the value of cystatin C in monitoring the renal function of patients receiving chemotherapy with platinum containing regimens. Methods: The blood samples of the patients receiving chemotherapy with platinum containing regimens were collected before and 7 days after the therapy to detect the cystatin C and creatinine,and the correlation between them was also observed. Results: Thirty-seven patients received 74 cycles of chemotherapy in all. The correlation between serum Cr and Cystatin C was confirmed (r=0.398,P < 0.01);Cystatin C was correlated with creatinine significantly (r=0.412,P < 0.01),and its correlation with CCr was no better than creatinine (r=0.412 vs r=0.567,P > 0.05);the serum Cystatin C level of the patients was higher after chemotherapy than before (P < 0.01). Sixteen of the patients received chemotherapy with cisplatin for 32 cycles,and their serum Cystatin C levels increased (P < 0.01);21 patients received chemotherapy with non-cisplatin for 42 cycles,and the results were the same (P < 0.01). The serum creatinine concentrations were not significantly different before and after chemotherapy in the two groups (P > 0.05). The abnormal rate of Cystatin C in patients receiving chemotherapy with cisplatin was higher than that with non-cisplatin chemotherapy (P < 0.01). Creatinine was detected abnormal only in one case. Conclusions: Cystatin C presents a much more sensitive clinical marker than creatinine for early assessment of GFR damage caused by chemotherapy with platinum containing regimens,but as there are some difficulties in clinical application,it could not act as a substitute for creatinine.