This paper presents a squat jumping control scheme for a 4-link robot. The 4-link robot model imitates the human body and the jumping motion is achieved by input-output linearization and output zeroing. One of the output functions in output zeroing control is based on trajectory planning of the center of mass in the vertical direction. The other functions are designed based on observation of actual human jumping for horizontal movement and attenuation of rotation of the body. The validity of the present scheme is shown by numerical situation.