This paper proposes the basic technologies in order to develop a wearable hand assistive system for daily life support. Current prosthetics have some problems for wearability. We focus on the load caused by weight of wearable system. The actuator is one of the heaviest parts in wearable systems. Therefore we propose to use the McKibben pneumatic artificial muscle which is lightweight and compact in size. At first, we propose a new method to control air pressure of artificial muscle without pressure sensor in order to reduce the size of system. Second, we investigate variable stiffness of human finger to perform human finger dexterity and simulate it by using our proposed polyarticular tendon drive system. ©2010 IEEE.