There is provided a respiratory waveform drawing system. The system includes: load detectors configured to detect loads of the subjects and output them as a load signal; a subject number determination unit configured to determine a number of the subjects on the bed based on a frequency spectrum of the load signal; a waveform separation unit configured to separate a load component of each of the subjects from the load signal outputted from each of the plurality of load detectors; a center of gravity position calculation unit configured to calculate a position of a center of gravity of each of the subjects based on the separated load component of each of the subjects; and a waveform drawing unit configured to draw a respiratory waveform of each of the subjects based on a temporal variation of the position of the center of gravity of each of the subjects.