A tire mount position detection system that detects each tire (31LO, 31LI, 31RI, 31RO, 32LO, 32LI, 32RI, 32RO) having a transmitter (41 to 48) is mounted to which wheel position in a vehicle having two axles (21, 22) in which each axle (21, 22) has a dual-wheel at each side, the tire mount position detection system comprising: a receiver unit arranged in the vehicle to receive a radio signal transmitted by the transmitter (41 to 48), wherein the receiver unit comprises a first receiver arranged at a position of which distances from respective wheel positions are different to each other, and a second receiver arranged at the same position as the first receiver in a front-rear direction of the vehicle and arranged symmetric to the first receiver with respect to the center of the axle (21, 22) in a width direction of the vehicle; a first measurement portion that measures first signal intensity (R1(x)), which is intensity of the radio signal received by the first receiver, for each transmitter (41 to 48); and a second measurement portion that measures second signal intensity (R2(x)), which is intensity of the radio signal received by the second receiver, for each transmitter (41 to 48); characterized by a calculation portion that calculates a difference of the first signal intensity (R1(x)) and the second signal intensity (R2(x)) and a total value of the first signal intensity (R1(x)) and the second signal intensity (R2(x)), for each transmitter (41 to 48); and a position detection portion that detects the wheel position to which the tire (31LO, 31LI, 31RI, 31RO, 32LO, 32LI, 32RI, 32RO) having the transmitter (41 to 48) is mounted, based on the difference and the total value, wherein the position detection portion detects: a width direction position of the transmitter (41 to 48) in the width direction of the vehicle based on the magnitude of the difference; a front-rear direction position of the transmitter (41 to 48) in the front-rear direction of the vehicle based on the total value; and the wheel position based on a combination of the width direction position and the front-rear direction position. a receiver unit arranged in the vehicle to receive a radio signal transmitted by the transmitter (41 to 48), wherein the receiver unit comprises a first receiver arranged at a position of which distances from respective wheel positions are different to each other, and a second receiver arranged at the same position as the first receiver in a front-rear direction of the vehicle and arranged symmetric to the first receiver with respect to the center of the axle (21, 22) in a width direction of the vehicle; a first measurement portion that measures first signal intensity (R1(x)), which is intensity of the radio signal received by the first receiver, for each transmitter (41 to 48); and a second measurement portion that measures second signal intensity (R2(x)), which is intensity of the radio signal received by the second receiver, for each transmitter (41 to 48); characterized by a calculation portion that calculates a difference of the first signal intensity (R1(x)) and the second signal intensity (R2(x)) and a total value of the first signal intensity (R1(x)) and the second signal intensity (R2(x)), for each transmitter (41 to 48); and a position detection portion that detects the wheel position to which the tire (31LO, 31LI, 31RI, 31RO, 32LO, 32LI, 32RI, 32RO) having the transmitter (41 to 48) is mounted, based on the difference and the total value, wherein the position detection portion detects: a width direction position of the transmitter (41 to 48) in the width direction of the vehicle based on the magnitude of the difference; a front-rear direction position of the transmitter (41 to 48) in the front-rear direction of the vehicle based on the total value; and the wheel position based on a combination of the width direction position and the front-rear direction position. a width direction position of the transmitter (41 to 48) in the width direction of the vehicle based on the magnitude of the difference; a front-rear direction position of the transmitter (41 to 48) in the front-rear direction of the vehicle based on the total value; and the wheel position based on a combination of the width direction position and the front-rear direction position.