To provide a portable wheel-weight detector in which a wheel at a vehicle to be measured can be positioned stably on a load mounting plate, which can perform a measurement precisely even when an uneven part exists on a load mounting face, which is small and lightweight and which is convenient to cary.

A wheel introduction part 2a is installed at the front part of a load mounting plate 2, a wheel fixation part 2b is installed at the intermediate part, and a wheel-retreat stop part 2c is installed at the rear part. As a result, a portable wheel- weight detector can be made small and lightweight. A wheel 30 can be guided easily to the wheel fixation part 2b, and the weight of the wheel can be measured precisely. A load introduction part 7C at a load transducer 7 is fixed firmly to the rear surface of the wheel fixation part 2b by using a fixing screw 5. A base 10 is attached to the bottom part of a load support part 7A via a bearing part 20 which is composed of a spherical seat 21, of a spherical seat 22 and of a ball 23. It is attached by using an adjusting screw 12 and a rubber washer 13 so that the load mounting plate 2 can be tilted forward and backward. Consequently, an uneven part on a load mounting face is buffered by the bearing part 20, and an axial load is applied to the load introduction part 7C so as to be measured precisely.