Abstract: This paper presents a NIOS II-based Single Event Effects detection system of asynchronous SRAM,which is used to evaluate the single-event-effect capabilities of anti-radiation hardened SRAM circuit.The detection system can be used for dynamic and static testing of asynchronous SRAM in four operating mode.The experimental data of five kinds'icons are obtained under the heavy ion accelerator by using the detection system with one kind asynchronous SRAM.Single-event-upset threshold、saturated-cross-section and in-orbit-error-rate are taken by statistical analysis of the results,and the results are compared with the same circuit abroad.Based on these experiment results,the assessment conclusion of the device is given at last.