Abstract: A kernel function method and the results of computing unsteady load on three-dimensional wings in transonic flow are presented in this paper. The method is based on linearized lifting surface theory. Local linearization is used for treatment of unsteady transonic flow about wings. A line doublet which represents the additional lift induced by shock movement is adopted in simulating the presence of a normal shocks and the appropriate shock boundary conditions are embedded.A new method dealing with the subsonic chord wise integration is introduced, and the procedures of numerical integration is simplified greatly. We also present procedures for calculation of downwashes. Both the downwash induced on subsonic region by supersonic region and shock doublet and the downwash induced on supersonic region by subsonic region H are included.Three numerical examples are given. The results are in good agreement with the experiments and data given in the references[1]and[6]. The present method is feasible as an approximate method dealing with unsteady load on three-dimensional wings in transonic flow. I