This paper is presented to solve the nonlinear dynamic buckling of sandwich functionally graded circular cylinder shells filled with fluid. Governing equations are derived using the classical shell theory and the geometrical nonlinearity in von Karman-Donnell sense is taken into account. Solutions of the problem are established by using Galerkin's method and Rung-Kutta method. Effects of thermal environment, parameters of geometric, volume fraction index k and fluid on dynamic responses of shells are investigated.