When the infrared focal plane arrays(IRFPAs) is using in the space,its performance can be reduced or it will be disabled.As the important part of the IRFPAs,the CMOS readout integrated circuit(ROIC),which is under a variety of radiations,is mainly reflected by ionizing radiation effect.After the experiment of giving space radiations to the IRFPAs CMOS ROIC chips,the function and the performance parameters of ROIC chips are tested.The affections of the radiations to the ROIC chips are also studied.The results of the radiation experiment give the referenced gist for the radiation resistant design of the IRFPAs CMOS ROIC.