Abstract: Based on a brief illustration of open end tendon transmission structures and their characteristic matrices, the concepts of velocity manipulability ellipsoids are introduced into tendon-driven finger mechanisms, and the condition for tendon-driven fingers to have isotropic velocity transformation characteristics is given. In terms of the mapping relationship between tendon velocity space and fingertip velocity space, and the kinematic coordinated equation established for the tendons of open-end transmission, the method to set up the velocity vector set of fingertip at any configuration of the finger is proposed. In order to evaluate the real velocity manipulating dexterity of the fingertip, a new quality measure is also presented, and examples are given to illustrate the analysis method of the manipulating dexterity of finger mechanisms.