In order to observe the difference in gene expression in the kidney of SHR and WKY rats, mRNA differential display was undertaken to screen differently expressed genes in the kidney of SHR and WKY rats aged 12 weeks by using T11G and AP6 primer. One cDNA fragment was identified in the kidney of SHR and was selected as interesting band. The techniques of T-A cloning, Northern hybridization, in situ hybridization and sequencing of the recombinant plasmid were used to determine the characteristics of differentially displayed cDNA fragment. The results indicate that it contains 170 base pairs and the incidence of homology with known genes is less than 80%, it was located in the renal tubule of SHR and no positive signal was found in the kidney of WKY.