Finding a stable trajectory is amongst pivotal subjects for bipeds, which are a type of legged-robots. To mimic human gait, biped robots are basically complex because of having numerous Degrees of Freedom. The main goal of this paper is to design a stable trajectory of gaits for a 9 links robot via Zero Moment Point stability criteria. The robot used in this paper is composed of 16 active joints with two toe joint. One of the aspects of human walking to design longer strides is to use a status in which the foot is rotated about its toe joint. Here, a gait type is utilized whereas the entire sole of the support foot firstly touches the ground then rotates about its toe axis as an active joint. To achieve an initial admissible equation for robot motions, a constraint is used for initial guess of pelvis motion. Then, by using a novel algorithm, the trajectory of the joints is calculated. Finally, by considering Zero Moment Point and a trial-error algorithm, the desired trajectory of the biped robot is obtained.