Nonvolatile memories play a critical role for storing significant data,the programs of micro control system and scientific observation data[1].Unfortunately,conventional charge non-volatile memories,EEPROM or PROM are hardly to suitable the new missions nowadays,such as the requirements of more than 10 years on-orbit service and ultra-deep space exploration missions,etc.Representation of novel NVRAM technologies of magnetoresistive random access memories(MRAM)utilize magnetic bits of a magnetic tunnel junction(MTJ)[2]to store binary data have inherently endurance to the direct ionization induced by the charge particle.Therefore,it is an ideal candidate general-purpose memory to be used in space-borne microelectronics.