Determination of the mean and variance of eigenvalues of simply supported rectangular plates with stochastic properties is presented by applying the random perturbation techniques of Boyce. Then, determination of the mean and variance of the displacement of a simply supported uniform rectangular plate with uniformly distributed viscous damping having a random value to a distributed random excitation is studied. The technique of Boyce is extended to the inhomogeneous equation for the plate in the latter case. It was found that for free vibration, the distribution of the variance of natural frequency is obtained in exponential form for the given exponential correlation functions of the material properties.