A drive system of an electric vehicle is disclosed. The vehicle has an arrangement optimized for characteristics of a hydrogen electric truck so as to ensure an available space inside vehicle body frames, thereby allowing a battery, high-voltage electric parts, a hydrogen tank, and the like to be arranged inside the vehicle body frames and increasing space utilization in the vehicle. The drive system includes a motor configured to drive the vehicle, a reducer or a transmission connected to an output side of the motor so as to change a rotational speed of the motor, and a rear axle configured to transmit rotating power output from the reducer or the transmission to vehicle wheels. The motor and the reducer or the transmission together with the rear axle are mounted on a suspension.