Abstract: As software is one of the important safety factors in a softwarcintensive and safety-critical system, c. g.,an integrated modular avionics(IMA) system, software safety is to be a mainstream research direction in the crossing fields between software engineering and safety engineering. The paper analysed firstly the meanings and extensions of software safety, and then gave a definition of it. Measuring models of software safety were then discussed. The paper focused on the state-of-the-art of software safety from a software engineering perspective about development processes,designed alternatives, assessment techniques and certification methods. The potential research directions of software safety were finally pointed out.

Key words: Software factor,Software safety,Software engineering,Safety engineering,Systems engineering,Safety-crib cal systcm,Intcgratcd modular avionics(IMA)