PROBLEM TO BE SOLVED: To realize accurate detection the position of foots and load even in a case where boundary part between right and left force plates are trodden.SOLUTION: A load detecting system 1 comprises force plates 2R, 2L arranged right and left sides and load detection sensors 5a to 5h detecting respectively fool load when the right and left force plates 2R, 2L are trodden. In addition, upon walking, the load detection sensors 5a to 5h detect position of foots on the right and left force plates 2R, 2L respectively. In a case where shift detecting means 7 determines shift into "running mode", each of the force plates are regarded as one force plate 2 to detect the position of foots. The shift detecting means 7 determines the "running mode" in a case where one time of load is detected in a predetermined time cycle and simultaneous loads are not detected by the right and left force plates 2R, 2L.
