This study proposes a novel MR-powered robotic system controlled by the magnetic force generated from MRI scanner. In the proposed system, originally developed MR-powered actuator unit, which contains ferromagnetic particle as a power source, and spherical positioning mechanism are used. These elements benefit to develop a remote needle tip positioning system using the MRI scanner. The potential application of this system covers the automation for under MRI inspections, especially for the cryoablation of breast cancer. In this paper, we report on the performance evaluation of the MR-powered actuator unit and also suggest the spherical positioning mechanism which can be activated by the actuator units.