Using the differential display technique (DDRT-PCR) originally developed by Liang and Pardee, we tried to isolate the stage-specific or tissue-specific genes in the developing human neural system (brain). With about fifty sets of arbitrary primers and anchored primers, DDRT-PCR was carried out to analyze the differentially expressed mRNAs between human fetal brains of different developmental stage or different parts of human fetal brain at the same developmental stage. About one hundred bands containing cDNA fragments of differential interest were cut out from the polyacrylamide gel, thirty-four of which were cloned and sequenced. They were accepted as novel cDNA sequences by GeneBank. In order to check the feasibility of DDRT-PCR, three of the thirty-four cDNA sequences were randomly chosen as probes for further analysis by dot blot RNA hybridization, and two proved to be specifically expressed in human brain.