To provide a rim for mounting a testing tire which can certainly mount a testing tire used for a tire characteristic test, a method to precisely mount a testing tire on a test equipment, and a method and a device for determination of a rim fitting ability after mounting the tire.

A rim body 11 comprising the first and the second rim members 11A and 11B for mounting a testing tire 1. On the periphery of the first and the second rim members 11A and 11B, a rim fitting sensor 30 having an ultrasonic vibrator 30a which applies ultrasonic vibration on the rim body and a vibration sensor 30b which detects a vibration level of the rim body is provided. The testing tire 1 is mounted thereon while applying a ultrasonic vibration on the rim body, and the vibration of the rim body after mounting a tire is detected. A rim fitting ability is judged by comparing the detected vibration level with a predetermined threshold value.