Abstract: An approximate solution is obtained for the diffracted acoustic field on a rigid smooth convex surface based on the uniform geometrical theory of diffraction(UTD).A diffraction model is constructed in which diffracted rays are used to calculate the sound pressure field at any point on the convex surface where the UTD is valid.Numerical results for the diffracted sound fields on spherical and infinite-cylindrical surfaces are presented,showing a good agreement with the analytical solutions.This solution can be employed to calculate the sound field on a convex surface in an efficient and accurate manner.