Up to now, three-dimension (3-D)finite difference models have been extensively used to simulate water current in coastal areas, lakes and reservoirs. The explicit time integration method is used in many of such mcxiels and thus the time step size is limited by the well-known CFL stability criterion. A three-dimension implicit finite difference model for wind-driven water current in a lake is developed in this paper. Stress terms, pressure terms and Corilic terms in the governing equations are represented implicitly in the model, and through analysing the stability of difference scheme, it is discovered that time step size of the scheme is essentially independent of CFL criterion. The proposed model is thus valuable in reducing compute time. The proposed model is first validated by a particular case where analytic solution is available in comparison with difference solution of the model, and then it is used to simulate wind-drivern water current in Moshui Lake. The real case shows that the calculated results of the mcxiel are rational and available, and can describe better the structural characteristic of wind-driven water current in a lake.