Abstract
This paper describes the design and implementation of Waist Module of Functional Modular Robot. This Waist Module controls center position of the gravity of upper module. This module solves the problem of the control gravity of center position of conventional Modular Robot. This Waist Module enables to design many modules of Functional Modular Robot without consideration for the problem of gravity of center position. We implement it and do some experiments. The result shows this module is effective.