This paper describes an experimental evaluation of a miniature force and torque sensor in robot-assisted minimally invasive surgery (RMIS). A sensor prototype including the mechanical system and sensing electronics is overviewed. A linear square based static decoupling method is introduced, design and use of a newly invented calibration platform is presented. A dynamic loading mechanism to simulate a heartbeat motion is described. The sensing ranges of the sensor prototype is ±30 N and ±30 N·mm with resolutions of 0.08 N (x, y directions), 0.25 N (z direction), and 2.4 N·mm (rotational directions). It also exhibits a good capability to follow the dynamic loads at a frequency close to a normal heart rate of an adult.