Abstract: Aircraft interacts with the ground through landing gear system, wh ile taxiing down the runway. Owing to the changed forces and moments acted on th e aircraft, the landing gear shocks, and consequently results in the shift of th e aircraft Euler angle. In order to study the aircraft taxiing characteristics, considering the aircraft’s attitude and rotation, the aircraft landing gear sys tem mathematical model is built including tire model, ole-pneumatic shock strut model, landing gear walking model and main wheel brake device model. Considering ABS(anti-skid brake system) control and nose wheel manipulation, the landing g e ar system model is applied to aircraft six degree of freedom model and been simulated. The si m ulation results show that the aircraft landing gear system mathematical model es tablished is correct. Moreover, it establishes the foundation to the research on the aircraft taxiing characteristics.