It is important from the viewpoint of prevention of the sea disaster to predict the process of oil dispersion on the sea surface flowing out from the tanker which has come into collision or smashed into the rocks. Some theoretical results are available in case of one-dimensional dispersion including the axisymmetric case. The object of the present investigation is to develop the simulation techniques for the process of two-dimensional oil dispersion under the arbitrary initial and boundary conditions including the effects of wind and tidal flow. After the introductory remarks in Section 1 some theoretical solutions are derived in Section 2 based on the procedure described in Refs. 1) and 2), where the oil flow and the flow in the water boundary layer is assumed to be turbulent. This analysis is extended to the two-dimensional case in Section 3 by using the finite element method applied to the shallow water equation including the wind and tide effect. Two different approaches are described where inertial terms are considered in one approach and neglected in the other approach. In Section 4 the general procedure for the prediction of two-dimensional oil dispersion is shown with some numerical examples by the combined use of theoretical solutions, experimental results, and the finite element approach. Section 5 contains concluding remarks.