A few of new structures, which represent technical characteristics of mini- bus design today, have been applied into development of a new type mini- bus. Modeling of the mini- bus with dynamics of multi- body systems was researched into by using the ADAMS software, and then validity of the vehicle model was verified. Furthermore the operational stability of the mini- bus was investigated and evaluated by simulation analyses such as step steer analyses, snake cornering analyses, braking analyses in line, as well as complicated course analyses and so on.