Abstract: The aerodynamic characteristics under the cruise condition of the whole configuration will benefit from welldesigned wing. Continuous adjoint method can be used to complex configuration because the computation of the sensitivity derivatives of cost function with respect to design variables is nearly independent with the number of design variables. Based on the adjoint method, the problem of drag minimization of wing with viscosity is studied in present paper. The flow control equation and the adjoint equation are solved numerically with a finite volume fourthorderaccurate compact scheme for spatial discretization and RungeKutta integration for time advancement. Finally, an effective threedimensional wing optimization aiming at some important project is carried out in this paper.