MRI is applying an electromagnetic (EM) wave for imaging. In application of EM waves, the heating effect will be applicable such as hyperthermia for cancer treatment. This paper examines heating effects of the small resonant devices using Radio Frequency (RF) signal generated by MRI. A small resonant device which is inserted in the body absorbs RF power, and its temperature can be increased. By this method, better heating efficiency and higher transmission properties will be realized. With using a simulator, transmission properties from an RF coil of the MRI to the small resonant device including signal power density and the SAR pattern are evaluated. Transmission properties can be obtained as a parameter of winding number of solenoid coil. In addition, the small resonant device is made on a condition as same as simulation and performed the experiments and measured the temperature rise using an optical fiber thermometer. The experimental results agree well with the simulation. From the results, it is found that the small resonant device is applicable for heating in human body.