A structure design and a mechanical design of a humanoid robot named HIWIN MAN are described in this paper. This humanoid robot with 23 DOFs (degrees of freedom) is designed so that it is able to accomplish some human-like motions. The height and the weight of HIWIN MAN are 59 cm and 4.5 kg, respectively. There are 2 DOFs on the head, 4 DOFs on each arm, 1 DOF on the waist, and 6 DOFs on each leg. In the structure design of HIWIN MAN, the design concept, actuators model and frameworks are described. In the mechanical design of HIWIN MAN, the 3D design and the mechanism dimension of the head, waist, arms, and legs are described. Finally, three basic walking experiments of HIWIN MAN are presented to illustrate that the proposed mechanical structure is able to let HIWIN MAN walk forward, turn, and slip effectively.