Experimental investigation of irradiation damage to InSb photodiode arrays and to 64 * 64 InSb infrared focal plane arrays have been carried out by using Co^60 as pray sources. A reduction of one order of magnitude of RoA, the figure of merit of the diodes, from 3.6 * 10^5～4.3 * 10^5Omega·cm^2 down to 2.5 * 10^4～ 2.7* 10^4 Omega·cm^2 was observed after a total dose of 5000 rad irradiation. Also, significant degradation of thermal imaging ability for 64 * 64 InSb staring focal plane arrays after total dose of 10000 rad irradiation or more was observed.
