A walking aid system for controlling a motion rhythm of a walker comprising: a sensor section for sensing the motion rhythm of the walker; a recording section for recording measurement values of the motion rhythm sensed with the sensor section; a target setting section for setting a target value for the motion rhythm of the walker; a timing generating section for generating timing signals according to both the measurement and the target value; and a stimulus generating section for generating rhythm stimulus that is recognizable by the walker, according to the timing signal generated with the timing generating section; wherein the timing generating section calculates timing for rhythm stimulus according to the measurements of the motion information data sensed with the sensor section and to the preset target values and generates timing signals, the timing signals generated are sent to the stimulus generating section and the walk of the walker is controlled with rhythm stimulus generated in the stimulus generating section to realize the target value of motion rhythm; characterized in that the sensor section has an acceleration sensor which, when used, is attached to a waist of the walker, the walking aid system being configured such that a walk locus of the walker in three dimensions is calculated from the acceleration information sensed with the acceleration sensor, wherein the walk locus for the walk motion in vertical, left and right directions is obtained assuming that the walk motion is periodic oscillating motion by the alternation of both legs, an acceleration information is integrated to obtain a walk speed, an average value of the walk speed for short term having periodical deviation is obtained as baseline of the walk speed, displacement from the baseline of walk speed is obtained as an estimated speed, the estimated speed is integrated to obtain a walking position, the average value of the walking position is obtained as baseline of the walking position, and displacement from the baseline of the walking position is obtained as a locus, and the walk locus for a walk motion in advancing direction is obtained assuming that an average walk speed and an amplitude of walk speed may be approximated with a regression line, an acceleration information is integrated to obtain a walk speed, the walk speed removed offset is obtained by using a difference between the walk speed and an average walk speed for short term, an amplitude of the walk speed removed offset is multiplied by a constant to obtain an average walk speed for short term, the amplitude of the walk speed removed offset and the average walk speed for short term are added to obtain an estimated walk speed, and the motion distance is obtained by integrating the estimated walk speed. a sensor section for sensing the motion rhythm of the walker; a recording section for recording measurement values of the motion rhythm sensed with the sensor section; a target setting section for setting a target value for the motion rhythm of the walker; a timing generating section for generating timing signals according to both the measurement and the target value; and a stimulus generating section for generating rhythm stimulus that is recognizable by the walker, according to the timing signal generated with the timing generating section; wherein the timing generating section calculates timing for rhythm stimulus according to the measurements of the motion information data sensed with the sensor section and to the preset target values and generates timing signals, the timing signals generated are sent to the stimulus generating section and the walk of the walker is controlled with rhythm stimulus generated in the stimulus generating section to realize the target value of motion rhythm; characterized in that the sensor section has an acceleration sensor which, when used, is attached to a waist of the walker, the walking aid system being configured such that a walk locus of the walker in three dimensions is calculated from the acceleration information sensed with the acceleration sensor, wherein the walk locus for the walk motion in vertical, left and right directions is obtained assuming that the walk motion is periodic oscillating motion by the alternation of both legs, an acceleration information is integrated to obtain a walk speed, an average value of the walk speed for short term having periodical deviation is obtained as baseline of the walk speed, displacement from the baseline of walk speed is obtained as an estimated speed, the estimated speed is integrated to obtain a walking position, the average value of the walking position is obtained as baseline of the walking position, and displacement from the baseline of the walking position is obtained as a locus, and the walk locus for a walk motion in advancing direction is obtained assuming that an average walk speed and an amplitude of walk speed may be approximated with a regression line, an acceleration information is integrated to obtain a walk speed, the walk speed removed offset is obtained by using a difference between the walk speed and an average walk speed for short term, an amplitude of the walk speed removed offset is multiplied by a constant to obtain an average walk speed for short term, the amplitude of the walk speed removed offset and the average walk speed for short term are added to obtain an estimated walk speed, and the motion distance is obtained by integrating the estimated walk speed.