Objective In order to improve the accuracy and efficiency of the measurement of range of motion (ROM) of human lower limbs and simplify process of ROM measurement,an automatic measurement of ROM of human lower limbs based on Kinect technique was proposed and tested in this study.Methods Fifty examinee were randomly divided into 5 groups,namely groups a,b,c,d and e,respectively,each group had 10 members.Using the human skeleton tracking technology from Kinect,the positions of the examinee's lower limbs were captured and tracked by processing the depth data of lower limbs' key joints.Then the information of ROM of hip and knee was output on human-computer interaction interface in real-time.By comparison with traditional manual measurement results,the accuracy of automatic measuring method could be verified.Meanwhile,with the aid of speech recognition and output technology,the mode of warning information transfer and the way of subject switch were optimized.Results According to the method of Grubbs-test and t-test,the ROM values | t | from the subjects' hip abduction (t =0.57,P =0.597),hip adduction (t =0.52,P =0.621),hip anteflexion (t =1.01,P =0.371),hip postextension (t =0.12,P =0.902),hip external rotation (t =0.00,P =1.000),hip internal rotation (t =0.34,P =0.753),knee flexion and extension (t =1.12,P =0.280) all were under the threshold value t0.025 (4) =2.776 on the premise of a level of significance α =0.05,which indicated that there was no significant difference between measured results and expected values(P ＞ 0.05).Conclusion The automatic measurement of ROM of lower limbs can be realized which can improve the measurement accuracy,simplify the measurement process and enhance the practicability of ROM of lower limbs measurement.