Abstarct: In this research, the buckling load of an axisymmetric elastic cylindrical shell has been determined analytically and the effects of the geometrical parameters on the buckling load have been investigated. The equilibrium and stability equations have been derived by the virtual work method by considering the first order shear deformation theory. The strain components have been determined by Green’s kinematic formula. After converting the governing equations to a dimensionless form, the perturbation technique has been used to solve the nonlinear equilibrium equations. The resultant values have been replaced in the stability equations and the buckling load has been determined. Also the buckling load has been determined by using the finite elements method and compared with the analytical results. The results show that the first order shear deformation theory is more effective than the classical theory for predicting the buckling load especially in moderately thick shells. The results have been presented as the graphs and tables.