In the progress of the genome projects, the most important purpose of molecular biology of the gene is to investigate the structure and function of not only single important gene but also the whole genome, that is the gene transcription and expression patterns of the whole cell. In order to resolve such complex problem, revolutionary research methods must be developed. Serial analysis of gene expression(SAGE), cDNA microarray, DNA microchip are the novel methods for fast and quantitative analysis of gene characteristics which are recently advanced in this background.