Objective:To investigate retrospectively the clinical significance the serum C-reactive protein(CRP) in patients with relapse of malignant tumor before and after chemotherapy. Methods:The values of serum CRP were quantitatively determined by immunoephelometry. Thirty-four patients with relapse of malignant tumor were served as the experiment group,and 22 patients with adjuvant chemotherapy after surgical resection were served as control group. Results:CRP elevation was found in 83.25% of patients with relapse of malignant tumor. No obvious change of CRP was found in patients with adjuvant chemotherapy after surgical resection. CRP was decreased in chemotherapy responders after chemotherapy compared to before chemotherapy,but it was increased in chemotherapy nonresponders. Median survival time was 8 months in patients with ineffective chemotherapy. Conclusion:The curative effect was inverse correlation with the CRP level and the increase of CRP after chemotherapy indicates the poor outcome. Maybe CRP could be served as a reference to diagnosis,curative effect and prognosis for patients with relapse of tumor.