The parellel light measurement and analysis system was designed and manufactured for research on kinematics of the whole lumbar spine.A loading frame was improved to decrease interference of experiment equipment for movement of lumbar spine.Along with load was changed,fresh human ligamentous specimens of lumbar spine were presented the different motion;The movement of three marks,which fixed in vertebrae,were separately projected to light screen of the system,kinematically recorded with video camera,inputted to image processing system.Then,according to prineiple of rigidity movement we proceeded with calculation,and obtained three-dimensional motion measurement of marks and kinematic characteristic of the whole lumbar spine.