Sea ice dynamics plays a pivotal role in describing sea-air interaction in polar regions. This paper discusses the behavior of ice dynamics and shows a momentum balance describing ice drift, the creation of leads and the building of ice ridge, and the nature of sea ice rheology relating the ice stress to the ice deformation and strength. A numerical is presented for the simulation of sea ice dynamical processes. The ice dynamical processes describe ice drift and deformation based on the principles of the conservation of mass and momentum, and contribute to determining the variation of ice thickness and open water or lead area in the ice-covered sea. In the the ice thickness distribution is described with three idealized levels:open water, level ice and rubble. The deformation funcdons are induced into the prognostic equations of the three variables and a parameterization method is employed to simulate the ice ridge and leads. For modelling the ice interaction, the sea ice is considered to be a nonlinear viscous compressible material obeying the viscous-plastic constitutive law. The numerical scheme for the model is outlined and discussed in the paper.The air and water stresses are obtained by using the conventional quadratic law from data or forecasting results of winds and currents. This model is applied to simulate ice drift for the Bohai Sea, the Bothnia Gulf of the Baltic Sea end the Labrador Sea, respectively. The model results show that ice drift in the Bohai Sea has a strong periodical change caused by tides. The creation of leads and ridges in the Bohai Sea are simulated and a sensitivity study of the ice rheology parameters is conducted. The ice model is linked to an atmospheric model with a boundary layer model for numerical sea ice prediction and the results for the Bohai Sea are presented in the paper.