The rutresistance properties of largestone flexible bases are studied, taking into consideration heavy loads and using computer simulation and numerous indoor tests. In computer simulations of largestone flexible bases, a calculation method was formulated for predicting asphalt pavement rut under dynamic loads. The method was based on the coupling of vehicle dynamic loads and pavement surface unevenness. The results of indoor testing and threedimensional numeric calculation under dynamic loads are confirmed by tracking observation results of a test road. We conclude that the rutresistance properties of largestone flexible base asphalt pavement built using lowgrade asphalt and low crush value high performance aggregate with reasonable gradation is no worse than that of the semirigid base asphalt pavement, and that ruts mainly are caused by the lateral shear.