In order to investigate the gait of Chinese mitten crab, a motion images recorded and analyzed systems was established with high speed camera and 3-D motion analysis software. The results showed that Chinese mitten crab performed alternating tetrapod gait when walking on smooth road. Adjacent ipsilateral and segmental pairs of legs alternated with each other; Subadjacent ipsilateral legs and diagonal pairs of legs moved together. Duty factor of each leg was (55.60±7.53)%, which indicated that Chinese mitten crab made its body more stable during walking through increasing support phase.