Abstract: Two types mechanism of micromanipulator appeared in recent years. It is the serial mechanism and the parallel mechanism. They possess their respective strong and weak points. Based on the complementary law, one new type which is called Serial-parallel Mechanism is presented in this paper. In order to evaluate the effects of the structural parameter errors upon the pose accuracy, a vector arithmetic method is applied to establish the relations between the pose accuracy and manufacturing tolerances, actuation errors, and connection errors of two stages. The sensitivity parameters affecting the micromanipulator pose are discussed. And some results which are very useful to the design and manufacture of the micromanipulator are derived. The analysis method can also be used on the accuracy analysis of other type parallel or serial-parallel mechanisms.