Abstract: Abstract: EDAC(Error Detection and Correction)based information redundancy is a well-known system level fault-tolerance technique for SEU(Single Event Upset)in space applications. Software-implemented EDAC technique is a substitute for hardware-implemented EDAC. The encoding and checking program is added to detect and correct memory errors through accommodate extra ECC（Error-correcting Codes）. The reliability of software-implemented EDAC would be analyzed for capability and the code rate of error-correcting code, the scrubbing interval and the number of program words protected. Simulation and analysis are presented to the random error of a single-bit upset, that the capability and code rate of the codeword, the scrubbing interval can be increased without appreciably affecting reliability, however reducing the number of program size protected would be obviously improve the reliability. It can provide important reference for application among the memory resource, real-time performance and reliability of choice.