An on-vehicle apparatus control system includes: a first on-vehicle switch and a second located farther from an on-vehicle reception unit than the first on-vehicle switch; an on-vehicle control device; and a portable machine. In a case where the on-vehicle switches is operated, the on-vehicle control device transmits a response request signal to the portable machine, the portable machine returns a response signal, and the on-vehicle control device controls an on-vehicle apparatus. The on-vehicle apparatus control system further includes a level switch. In a case where the first on-vehicle switch is operated, the level switch switches transmission intensity of a portable machine transmission unit or reception sensitivity of an on-vehicle reception unit to a first level, and in a case where the second on-vehicle switch is operated, the level switch switches the transmission intensity or the reception sensitivity to a second level higher than the first level.