This paper studies Second order Shear Deformation Theory (SSDT), as a higher order shear deformation theory, for an axisymmetric functionally graded shell of revolution with variable thickness. According to symmetrical condition, there is not any displacement and any variation along the symmetric direction. The governing equations of proposed shell are derived by virtual work principle. As a special case, the governing equations are rewritten for a cylinder with variable thickness and non-uniform internal pressure. The comparison between current work, classical theory and First order Shear Deformation Theory (FSDT) are illustrated with some numerical results. Non-homogenous material, boundary condition effects, non-uniform pressure, arbitrary curvature with variable thickness and nonlinear displacement feld are some advantages of current work. The optimum design of shell is the main goal of current approach that has a wide industrial application like aerospace engineering.