Abstract. In the present paper, the asymmetrical nonlinear response of a clamped functionally-graded shallow spherical shell is subjected to uniform external pressure. It considers the e ects of thermal stresses by both of the theories: Classical Laminate Theory (CLT) and First-order Shear Deformation Theory (FSDT). Material properties are graded in the thickness direction according to the power-law distribution in terms of the volume fraction of the constituents. Mechanical and thermo-mechanical properties are assumed to be temperature-independent and linear elastic. All of the governing equations are derived by aid of rst-order transverse shear deformation theory considering geometrical nonlinearity. The nonlinear di erential equation system is solved by Galerkin method. Buckling and post-buckling analyses have been done according to one-term deformation mode by the closed-form relation of load-de ection that shows the equilibrium path. Parametric studies are conducted to bring out the e ects of shear deformation on the equilibrium path in di erent geometries and boundary conditions. Numerical results are presented in graphical arrangement, showing the geometrical nonlinear equilibrium paths. The e ects of shear deformation on the equilibrium path are considered by comparing the results of FSDT and CLT, and they are veri ed by nonlinear nite-element method.