in wheel drive system taken along line a a in fig1 in the present invention the reason that the position of the motor is determined in this way is for maximizing the size of the motor without interference with the chassis even if the wheel vertically bounces in running or turns by the steering angle in turning a space that is not occupied by the motor corresponding to the amount of offset of the motor is generated at the rear and lower portion inside the wheel as illustrated in fig1 accordingly a suspension is more freely disposed at the lower portion as illustrated in fig1 a brake caliper 20 can be easily disposed opposite the side where the motor is offset inside the wheel therefore in the configuration of the system of the present invention the center of the motor is positioned at a predetermined distance ahead of and above the center of the axle as illustrated in fig1 when seen to the direction of outside from the inside of a vehicle the caliper 20 is positioned behind and above the center of the axle and a strut mount a mount for a lower arm 40 and a tie rod 50 are disposed above under and behind and under the center of the axle respectively referring to fig1 and 2 in an in wheel drive system 100 according to an exemplary embodiment of the present invention a motor 110 may be disposed inside a wheel 10 with the center c2 of the rotational axis ahead of and above the center c1 of the wheel 10 that is the motor 110 may be positioned inside the wheel 10.