In order to discuss the strategy of the numerical calculation of three dimensional unsteady free surface flows, the computer program of the finite element method with adaptive mesh refinement procedure is developed and some numerical results are obtained. This program is composed of several procedures, such as the automatic mesh generation, N-S (Navier-Stokes Eq.) solver by FEM, the adaptive mesh refinement and the band width reduction. Delaunay triangulation algorithm is applied to the automatic mesh generation. Arbitrary Lagrangian Eulerian FEM is applied to theN-S solver. Gibbs-Poole-Stockmeyer and Gibbs-King Algorithms are applied to the reduction of band width. And, the mesh refinement procedure for three dimensional flows is newly developed. Some numerical results are obtained by the above mentioned computer program. A data structure which is sulitable for the vectorization of the computer program is proposed.