According to the theories of the structure synthesis of parallel robot mechanisms, a new 3-DOF parallel manipulator with 3-rotation was synthesized and investigated. The manipulator consists of a moving platform, a fixed base, four kinematic chains of UPS and a restricted support chain. One of the four UPS legs is passive whereas each of the remaining three legs is driven by a linear actuator. To gain better understanding of the mechanisms, a methodology for analyzing the kinematics of such manipulator was presented subsequently. Finally, a case of a tunnel erecter mechanical arm was used as an example to illustrate the methodology.  