A novel nanoscale temperature measurement system using polarized near-field light which enables the high spatial resolution at nanoscale has been developed. In this measurement system, the temperature dependence of the rotation of the polarization plane in near field is detected. However, the signal light variation is extremely weak, therefore, more sensitive measurement system is required. In this paper, we proposed a novel high sensitive nanoscale temperature measurement method. In addition, this paper reports the analytical and experimental results by using platinum nanostructures in order to confirm the validity of the measurement principle.