A new type of humanoid flexible robot hand is developed using the selfdeveloped pneumatic flexible joint. The robot hand was 1.5 times the size of the human hand and each finger was composed of two pneumatic flexible joints. The fingers deformation was controlled by robot hand by regulating the pressure in each joint to grasp the objects. The kinematics experiments under various air pressures were made on pneumatic experimental platform by making use of three dimensional (3D) motion capture system. Furthermore, the workspace of robot hand was examined and the grasp experiments were completed. The experiments show that the robot hand has good flexibility and shape adaptability and it can accomplish a variety of grasp patterns to grasp different types of objects. The maximum and minimum diameter of the holding objects with five fingers is 220 mm and 50 mm, respectively. The maximum mass of the holding objects is 1 kg.