This book presents the effect of random system properties on linear and nonlinear free vibration response of elastically supported laminated composite plate in thermal environments using micromechanical approach. The system properties such as thermo-material properties, fiber volume fractions of respective fiber and matrix constituents and foundation parameters are modeled as independent random variables. The temperature field considered to be uniform and non-uniform temperature distributions over the plate surface and through the plate thickness. The material properties of the composite are affected by the variation of temperatures and based on micromechanical model. The basic formulation is based on higher order shear deformation plate theory and general von-Karman types of nonlinearity. A direct iterative based C 0 nonlinear finite element method in conjunction mean centered first order perturbation technique is out lined and solved the stochastic nonlinear generalized eigen value problem. The developed stochastic procedure is usefully used for thermally induced nonlinear free vibration problem based on micromechanical approach with a reasonable accuracy.