Abstract: Objective: To study the value of serum prealbumin(PA) and tumor specific growth factor(TSGF) in diagnosis of malignant tumor.Methods: By using the immunoturbidimetry and chemical method the serum PA and TSGF were determined in 169 cancerous patients,and 24 benign tumor patients,and 30 healthy subjects.Results: The serum PA was apparently higher in benign tumor group than that of the health normal group(P<0.01),but TSGF had no difference(P>0.05);In cancerous group(besides kidney cancer patients) the serum PA was all significantly lower(P<0.01),TSGF was all significantly higher(P<0.01) comparing with the healthy comparison group.The positive rate of the PA was 72.19%,the specificity was 93.33%;the positive rate of the TSGF was 62.13%,the specificity was 86.67%;the positive rate of two union detection was 79.88%.Conclusions: The serum PA、TSGF of cancerous patients obviously changes,the union detection is helpful to improve diagnostic coincidence rate of cancer.