Abstract: To choose mechanism type of micromanipulator, kinematic performance of two 3-PUUtranslational parallel mechanisms with different guide ways-perpendicularity guide and intersectantguide is investigated. Inverse kinematics of the two mechanisms is analyzed, and then constant inverse Jacobian are derived. Herely workspace volume and dexterity of two 3-PUU mechanisms are respectively compared under same dimension parameters. The result: shows that workspace of the 3-PUU mechanism with vertical guide has bigger, and both of them is the same dexterity. Therefore the kinematic performance of the mechanism with vertical guide is better than that with intersectant guide.