MiniQuad- II is a modular four-legged walking robot. In order to research dynamics and kinematics of the robot, based on inner relation of different simulation software, three-dimensional entity model of four-legged walking robot MiniQuad-II is built up with SOLIDWORKS software firstly. Then, the model is leaded in ADAMS software, dynamics and kinematics of the robot are simulated, the relevant process is described in this paper. As an example, the robot MiniQuad-II walking along straight line is investigated, the dynamics of the robot are analysed with ADAMS. Further, the influences on dynamics properties for the robot are discussed when structural parameters of the robot are changed. Results can be used to optimaze robot structure and determine its final characteristic parameter.