The establishment of taxiing model for the Unmanned Aerial Vehicle (UAV) is the basis for control law design and real-time simulation system development of the UAV's taxiing in take-off and landing.We established the landing gear model and tire model of a wheeled UAV.The quality of UAV was divided into elastic support quality and rigid support quality.Analysis was made to the dynamic characteristics of the two parts in the UAV's taxiing phase, and the taxiing model of a wheeled UAV was established.Simulation tests of accelerated taxiing (take-off) and decelerated taxiing (landing) were made to the model, and the result show that the model is correct.