Abstract: An interpolation method is proposed for the surface velocity of cylindrical shell structures. The surface velocity is expressed by the Fourier series in the circumferential direction and the piecewise Lagrange function in the radial direction. The coefficients of the series expression are computed from few measured surface velocity. Once the coefficients are obtained, the series expression can be used to calculate the velocity at other positions on surface of the cylindrical shell structures which can avoid the errors of conventional interpolation methods and errors caused by discretization. Numerical examples demonstrate that the interpolation method can get smooth velocity distribution on the surface which is satisfactory for predicting the acoustic radiation based on few measured surface velocity. Finally, the accuracy and applicability of the interpolation method for the prediction of acoustic radiation from cylindrical shell structures are experimentally validated.