In the walking process, the human body shows regular periodic motion, especially upper and lower limbs, which reflect the individual’s unique movement pattern. Human gait is an attractive modality for recognizing people at a distance. Compared to other biometrics, gait has some unique characteristics. The most attractive feature of gait as a biometric trait is its unobtrusiveness, i.e., the fact that, unlike other biometrics, it can be captured at a distance and without requiring the prior consent of the observed subject. Most other biometrics such as finger prints, face, hand geometry, iris, voice, and signature can be captured only by physical contact or at a close distance the recording probe.-In the walking process, the human body shows regular periodic motion, especially upper and lower limbs, which reflect the individual’s unique movement pattern. Human gait is an attractive modality for recognizing people at a distance. Compared to other biometrics, gait has some unique characteristics. The most attractive feature of gait as a biometric trait is its unobtrusiveness, i.e., the fact that, unlike other biometrics, it can be captured at a distance and without requiring the prior consent of the observed subject. Most other biometrics such as finger prints, face, hand geometry, iris, voice, and signature can be captured only by physical contact or at a close distance　the recording probe.