Abstract: The paper presents a mathematical modeling study on the gaitstability control of a 17 degrees of freedom biped robot, based on ZMP theory andthe Pose Transformation Matrix, with the mathematical description of relativecenter of gravity and relative reference frame. The proposed mathematical modelcan describe the stability control of robots. It is shown, by Matlab mathematical computation and emulation study, that this model can describe the walking rules of biped robots, which means thatgait stability control of biped robots can be achieved.The whole model is encapsulated into a visual system by VC++ so that themodel can be brought under a practical control, thus providing a technicalsupport for the study of real-time control of future robots.