To screen radiation-sensitive genes with uniform background levels in human peripheral blood, which can be used as biomarkers for radiation injury, peripheral blood samples from three healthy adults were exposed to gamma-rays with dose of 0, 0.75, 2 and 6 Gy. The total RNA was extracted from the whole blood and differential gene expression profiling was analyzed using microarray at 2 h after irradiation. The results showed that 15 differential expressive genes with a relatively uniform background were found: ISG20L1, TRAF4 and TRIAP1 were up-regulated over 2-fold at 2 h after 0.75, 2 and 6 Gy irradiation; LOC345537, POLH, SPIB and TNFSF9 were up-regulated over 2-fold, and TCL1A was down-regulated over 2-fold at 2 h after 2 and 6 Gy irradiation; C12orf5, DDB2, GADD45A, MADCAM1 and RPS27L were up-regulated over 2-fold at 2 h after 6 Gy irradiation.Cited