Serial analysis of gene expression (SAGE) is a powerful technique designed to analyze the information of gene expression. It can not only immediately analyze thousands of genes in detail, but also find new genes. Therefore SAGE is an effective tool of qualitative and quantitative research for gene expression. Recently the SAGE method is widespread applied in cancer research, understanding pathways involved in tumorigenesis and identifying novel diagnostic and therapeutic targets. It is implied that SAGE in implications for cancer research, diagnostic and targeting process will have a great impact on cancer research.