Quadruped robots can perform tasks in the environment with rough terrain. And the mobility and versatility are the most important reasons for building quadruped robots. In this paper, gait analysis and implementation of a simple quadruped robot are presented. First, the biological gaits and the quadruped gaits are summarized and compared. Then, a normal quadruped gait, symmetrical or asymmetrical, is characterized by eight parameters. A mathematical model for this method is development. Thirdly, in order to verify the suggested analysis model, a simple quadruped is built up for experiment. The robot consists of twelve joints. Its structural variables are laid out according to walking simulation and energy consumption simulation during locomotion. Finally, a walking experiment is conducted according to the mathematical model. The result of the experiment shows that the suggested gait analysis model is suitable for a quadruped.