Advances in molecular biology contribute to the understanding genetic mechanism of psychiatric disorders. They have renewed hope for the discovery of disease relevant gene. However, the results somewhat confused. And we will wait for a long time for the application of gene therapy in schizophreniar. Fortunately we could classified the schizophrenia with genotypes of dopamine and serotonin receptors. It is expected that this genetic classification could provide key strategy for the therapeutic application in biological treatment for schizophrenia. The purpose of this article is to call attention of the institute participants to linkage, association, mRNA expression, genotypic classification and to the need for more systemic research. The author summarized the modified methods which were done in his laboratory in appendix.