Many different quadrupedal walking patterns (gaits), such as “walking”, “trotting”, “bounding” and “galloping” can be generated by systems of coupled central pattern generators (CPG). However, the physiological mechanisms for the walking patterns are unclear. As a result, from an engineering viewpoint, many different mathematical models have been proposed to describe these walking patterns. In this report, we propose a hard-wired CPG network based on Rybak's model that can reproduce quadrupedal locomotion walking patterns. In this network, we use the beating model proposed by Hoshimiya et al. and the bursting model proposed by Maeda and Makino. The main purpose of this study was to reproduce the typical walking patterns; “walking” and “bounding”, with a hardware model, and to switch between these patterns using only one parameter, which can be interpreted as voltage stimulation from the midbrain locomotor region. We found the transition from the “walking” to the “bounding” behavior to be due to a relative weakening of the coupling between the CPGs in the network by stimulation from the midbrain locomotor region.