This letter conducts a thorough comparison between two temperature compensation methods for resonant micro-electro-mechanical-system (MEMS) sensors, i.e., 1) a newly proposed in-situ temperature compensation technique based on a multiple parameter decoupling (MPD) using a single resonant MEMS sensor subject to blue-sideband excitation, and 2) the prevailing method utilizing a temperature sensor, which, in this letter, is a resonant thermometer in close vicinity of the sensor. Experimental results show that the MPD-based in-situ temperature compensation method offers better noise performance, long-term stability (fourfold at 1000s integration time) and application simplicity, compared with the compensation method using an additional thermometer, affirming that the proposed subject is of considerable potential for true in-situ temperature compensation for high-precision resonant MEMS sensors.