Wearable sensing devices for gait recognition is currently one of the most active research topics in locomotion analysis. This strong interest is driven by the promising applications in body sensors. Gait recognition concerns the detection, processing and analyzing of bio-mechanic signals. This paper provides a comprehensive survey of research on gait recognition based on wearable sensing system. The emphasis is on wearable sensors based on biomechanics theory. A general gait recognition system is exhibited. The applications in various fields are discussed to prove the technical feasibility. Finally, some research challenges and future directions are discussed.