This report deals with wall effect on the trailing vortex shedding angle of a rectangular plate wing with low aspect ratio. The rectangular plate wing moves obliquely in the proximity of a uniform wall. On the basis of Bollay's wing theory, calculation of the shedding angle including wall effect is made by using an image of the plate wing. The integral equation which determines vorticity distribution has also unknown quantity of trailing vortex shedding angle. This equation for the shedding angle can be solved by iterative procedure. It is indicated that the shedding angle increases with decrement of distance from the wall. Caluclated values of the shedding angle are compared with observed results obtained from a flow-visualization technique by means of dye tracer method. The calculated values agree qualitatively with the experimental results. Furthermore, variations of hydrodynamic forces on the plate wing with change of the shedding angle are discussed through the results of calculation and experiments.