Abstract: Nondestructive testing(NDT) of the rail in service is one of the most important tasks about the security in the rapid development of hi-speed rail in China. NDT is the key technique used to guarantee the safety of rails in service. The present paper comprehensively reviews the NDT methods and systems in use around the world for rail flaws inspection. It introduces a review of the current state-of-the-art in NDE of railways coupled with a discussion of future developments and new detection approach in the field.