Objective: To screen the differential expression genes of Kanglaite Injection in treating cancer cachexia. Methods: mRNA was extracted from the blood cells of T739 animal model of C.C., hybridizated respectively on 20S gene chip. Analysis discuss on differential expression genes was carried out. Results: 5 differential expression genes were obtained. Among these genes, 4 genes were up-regulated and 1 gene was down-regulated. Most of these genes were related with immunity and metabolism of tumor. Conclusion: cDNA microarray for analysis of gene expression patterns is a powerful method to identify associated genes of Kanglaite.