Abstract: Several thermal convection madels in the mantle with a moving upper boundary expressed "by plate absolute motion model AMI-2 and different thermodynamical parameters are investigated in this paper. Results show that fhe mantle flow is driven by the plate motions when the Rayleigh number of the mantle is less than 10000（529.41） and two components of plate motions （poloidal and toroidal） almost have same power. With the increasing of Rayleigh number the convection patterns apear more complicated: 1. the rate of plate motions is smaller than the rate of under laying mantle flow, 2. two layers convections apear in some regions. 3. the spectum of mantle flow is changeable, 4. the weight of toroidal componet in the mantle flow becomes smaller.