Abstract: An inverse aeroacoustic problem on rotor/stator interaction is investigated,which aims at reproduction of the unsteady pressure distributions on the stator blade according to the sound pressures at a limited number of points in space.On basis of the linearized Euler equation,the sound pressure is correlated with the unsteady pressure distributions on stator blade surface in the form of the Fredholm integral equation of the first kind.In order to solve this kind of typical ill posed problem,the least square method,which combines singular value decomposition technique and Tikhonov regularization method,is used,and the discrete Picard condition is employed to analyze the ill posed problem.The regularization parameter is chosen by Generalized Cross Validation method.The numerical results show that the reproductions are feasible on the conditions that the signal to noise ratio is not very low.