This paper mainly describes the design and development of the humanoid robot arm. First, according to the requirements of tasks and anthropomorphic characteristics, the 7-DOF humanoid arm with non-offset S-R-S configuration is identified by evaluating four alternatives. The humanoid arm is accomplished with modular design, and is composed of links and modular joints. Cables between joints pass through the internal hollow shafts along the arm axis. Second, three different sizes of modular joints are built, which are multisensory and highly electromechanical integrated. The design of modular joint is descirbed in detail, including joint structures, electronics, fail-safe brake and multisensory systems. And also, the arm architecture and structure design, envelop, and feasible control strategies are discussed. Finally, the 7-DOF humanoid arm is built with high stiffness and degree of modularity. It is capable of handling 10 Kg payload with full arm extension in 1-g condition and total mass is less than 18.5 Kg.