Abstarct: In this research, frequency analysis of the reinforced truncated conical shell under external load is presented. The von Karman nonlinear strain-displacement relation is used to obtain the equations of motion of this structure included its reinforcing rings and stringers. Using Donnell-Mushtari-Vlasov theory and Hamilton's principle, these equations which are a system of coupled nonlinear partial different equations with variable coefficients have been drived. The nonlinear Galerkin method along with homotopy perturbation method (HPM) have been applied to solve the equations of motion. The extracted results are in good agreement with those of other research works. Finally, a parametric study is performed to investigate the effects of the various parameters such as thickness of the shell, number of rings and stringers, on linear and nonlinear natural frequencies and primary and secondary resonances.