One strain bacterium was isolated from purple soil of Sichuan basin. It was subject to Bacillus according to analysis results of 16S rDNA. The effect of its biosorption to Sr2+ under γ-ray radiation was studied in this paper. As for the whole kinetic biosorption curves, the results show that bacterial growth rates of test groups have retardation phenomena compared to the control groups without radiation. Such as the appearance of biosorption equilibrium retarded 1.5 d while the max growth rate retarded 0.5 d after the radiation. SEM analysis showed that the bacterial cells had abnormity distortion after radiation. This proved that γ-ray radiation can bring obvious damage to experimental bacterial cells. FTIR analysis results indicated that bacteria cells were damaged by radiation and Sr2+ has cooperation damage effects with radiation in aqueous condition, and the bacterial cells of log phase are easier to be damaged by coming forth radiation than those of lag phase. This radiation damage under different radiation condition mainly leads to that the characteristic peaks of amylase, protein amide and lipids on bacterial cells are slightly shifted.