PROBLEM TO BE SOLVED: To prevent the occurrence of an undesirable state on durability of components even when a manual switch is turned off while at least one of a travelling motor and an auxiliary motor is rotating, in a motor control system.SOLUTION: A motor control system 12 has: an ECU 20 for controlling a travelling motor 14 and a deck motor 28； a manual switch 29 for outputting a signal representing ON or OFF to the ECU 20； and an ECU power supply switching section 35. The ECU power supply switching section 35 supplies power to the ECU 20 from a battery 18 when an ON instruction signal Si is input from the ECU 20 and interrupts power supply to the ECU 20 when a key switch 30 is turned off and an input of the ON instruction signal Si from the ECU 20 is interrupted. The ECU 20 maintains the ON instruction signal Si to the ECU power supply switching section 35 while at least one of the travelling motor 14 and the deck motor 28 is rotating, when the key switch 30 is turned off.
