A biological information monitoring system (100) for monitoring various biological information on a subject (S) on a bed (BD), the system including: a plurality of load detectors (11, 12, 13, 14) to be placed in the bed or under legs of the bed, each of the plurality of load detectors being configured to detect a load of the subject and output the detected load as a load signal； a signal separation unit (32) configured to separate components each corresponding to each of a plurality of frequency ranges, from the load signal outputted from each of the load detectors； and a center of gravity position calculation unit (33) configured to calculate a center of gravity position of the subject based on the separated components.
