Among the researches into hydraulically interconnected suspension (HIS) in the past decade, the sensitivity of some key design parameters to the ride comfort and the mode of the vehicle has been well studied. In respected of handling performance, the past researches have focused on the roll performance during steering process and the road holding capability on straight road but the influence on the understeer-oversteer characteristic has never been detected. HIS is the suspension system that can directly matter the vertical force on the wheels and accordingly it is able to influence the lateral load transfer ratio (LTR) from the inside wheels to the outside ones in the steering process. The change of the load transfer distribution varies the slid-slip characteristics on the front and rear axles which highly correlate to the steering characteristics of the vehicle. This paper introduces the model of the vehicle fitted with HIS used to conduct the simulation analyses. The steady-state steering maneuvers are simulated to study the effects of some parameters on the steady-state understeer-oversteer characteristic. The fishhook maneuvers are simulated to investigate the transient understeer-oversteer characteristic. The simulation results demonstrate that the design parameters of HIS system can affect the understeer-oversteer characteristic and the corresponding simulation results of LTRs on the axles are exhibited to discuss the principles.