Abstract: In order to realize the stable and rapid omni-directional walking gait, and overcome such shortcomings as complexity in multi-rigid-body dynamics model and ignorance of step connections in other omni-directional motion strategies, a general kinematic parametric outline is proposed to describe a single step, and constraints among paces are described based on a newly reported omni-directional vehicle model. An inter-step transition algorithm is generated with these constraints. A standard working condition is also provided to evaluate the quality of omni-directional gait. Dynamics simulation and physical robot experiments prove the validity of the method, as well as the necessity of inter-step transition algorithm.