The diffraction problem appeared in the ship-wave interaction problem is treated by making use of the slender body theory under the short wave assumption. A solution which is valid in the bow near field as well as in the midship near field is derived and it turns out to be able to descrive the 3-D effect of the interaction of incident waves with a ship hull. This solution is thougth to be the extention of Faltinsen's³⁾ in the meaning that it is valid at the vicinity of bow and also the extention of Maruo's⁴⁾ in the meaning that it can treat not only zero forward speed case but also forward speed case. The wave load distribution calculated by the present method shows strong x-dependance, which can easily be attributed to the cumulative effect of the slowly varying source density function which is a representation of the effect of the interaction between incident waves and ship hull. By use of Green's theorem, the wave load can be calculated by the asymptotic behavior of the solution for the generalized radiation problem in which the 2-D Helmholtz equation is the governing field equation. Some heuristic numerical results are presented for a ship with circular cross section.