This main purpose of this thesis is to study dynamic balance during walking or under external forces for biped robots, and also to make biped robots to enhance stability during walking and standing. The accomplishment of dynamic equilibrium for the biped robots results from the builtin-in dynamic control programs which are written in Nios development environment. To get the pressure values by the pressure sensors of biped robots, we could use the control algorithms to compute and decide the actual Center of Gravity (CoG) position and also to determine whether the resultant CoG falls in the area of supporting polygon for a biped robot. Furthermore, we could use the fuzzy controller to compensate errors due to the differences between the actual CoG and the theoretical CoG. The objective is to make CoG to fall in the supporting polygon area, and then the biped robots will walk more steadily and so improve the overall stability when standing.