A biological information monitoring system for monitoring a biological information on a subject (S) on a bed (BD) includes: a plurality of load detectors (11, 12, 13, 14) which are to be placed in the bed or under legs of the bed, and which are configured to detect a load of the subject, a load separation unit (32) configured to separate a load component which oscillates according to a heartbeat of the subject, from the load of the subject； and a center of gravity position calculation unit (33) configured to obtain a position of a center of gravity of the subject based on the load component which oscillates according to the heartbeat of the subject.
