Objective To analyze the gait kinematics parameters of patients with unilateral leg amputation after wearing prosthesis using the computer assisted rehabilitation environment (CAREN) gait assessment system,and the reasons for the differences.Methods Nine patients with unilateral mid-leg amputation were selected as the prosthesis group,and 11 healthy subjects were selected as the standard group.The gait kinematics parameters of the two groups were collected,processed and analyzed by using the CAREN gait evaluation system.Results The gait phase index of the prosthetic limb group was (0.88±0.04).Significant differences were observed between the prosthetic and healthy limbs in terms of step length,stance phase percentage,maximum hip extension angle and maximum knee flexion angle,maximum dorsiflexion and plantar flexion angle of the ankle joint during the stance phase,as well as the dorsiflexion angle of ankle joint during heel strike to the ground (P＜0.05).Moreover,there were significant differences between the affected limbs of the prosthetic limb group and limbs of the standard group in terms of the walking speed,gait cycle,stride length,percentage of stance phase,hip flexion angle,knee flexion and ankle dorsiflexion during heel strike,maximum hip extension and flexion angle,maximum dorsi-and plantar-flexion of ankle joint during stance phase (P＜0.05).Conclusion The relative symmetry of the gait of the unilateral leg amputee is (0.88±0.04),with their kinematics parameters of the prosthetic limb significantly weaker than those of the contralateral side and the healthy controls.