Upon determining a physiological state of a seated person on the basis of measurement results of some of plural sensors, the sensors are easily and properly selected. A system includes sensors that measure measurement values to be changed on a seating surface of a seat, and a determination device. The determination device includes a storage unit that stores association relationships set by associating each area with some of the sensors, an area identification unit that identifies an area in which the coordinates of a gravity center of the seated person are located among the areas, a sensor selection unit that selects the sensors associated with the area identified by the area identification unit from the association relationships stored by the storage unit, and a determination unit that determines a physiological state of the seated person on the basis of the measurement results of the selected sensors are provided.
