Abstract: The influence coefficients at the roof and floor, sidewall and centerline of wind tunnel due to the line sources or vortices have been computed using the modified vortex-lattice method, for the purpose of utilizing the wall pressure method suggested by Hackett to the wind tunnel with non-rectangular cross section. The calculation and comparision of the test data on the same model,using the influence coefficients obtained from the image method separately,are also carried out. Finally, the effects of the fillet size over corrected results obtained from different methods are discussed.