This paper presents a useful analyzer system for human movement stability, which is composed of two developed sub-systems. One is a system of acquiring time series data of the person's movement factors. Another is a system of analyzing the person's movement stability. The setup of acquiring data system, which is a personal computer-assisted, employs two CCD digital video cameras and a force-plate sensor system, which are controlled on simultaneously. Time series data of 3-D coordinates on major joints are measured from a video recorder system using image processing and videometry. Time series data of each foot pressure are measured from a force-plate sensor system. However, the serial measurement data, i.e., the 3-D location of each knee while walking, center body gravity (COG) and each foot pressure while standing, are difficult to analyze directly the characteristics of movement stability, because of their complex fluctuations in feedback control among their variables. For a spectral analysis, utilizing AR (Auto Regressive) modeling, the power spectrum and the impulse response of movement factors enable analysis of their dynamical relations. This useful analyzer system for human movement stability provides new medical evaluation in rehabilitation and physical fitness.