This research develops a Pneumatic Actuated Seating System (PASS), a new human-machine interaction tool to aid in chair design. The seating system is powered by thirty six designed intelligent pneumatic actuators. Three attributes are proposed for chair design namely shape, stiffness and damping characteristics. These facilitate investigation of chair shapes from spring and damping effect for seat and backrest surface. The proposed attributes will quantify the relationship between human styles of seating with the developed seating system. This research tool will be used as experimental apparatus for chair design in the area of customized and specialized seating. The system design, instrument and sitting tests are presented. Three subject sitting tests were done to evaluate the current system and confirm the function ability for further optimization technique in selecting the best parameters.