Abstarct: In this research, buckling and ratcheting behavior of stainless steel cylindrical shells under cyclic combined and axial loadings were studied numerically and experimentally. In ratcheting analysis, the shells were fixed normal and oblique at angle of 20° with respect to the longitudinal direction of the shells and subjected to force-controlled cycling with non-zero mean force at the end of them which causes the accumulation of plastic strain or ratcheting phenomena. Experimental tests were performed by a servo-hydraulic INSTRON 8802 machine. The numerical analysis was carried out by Abaqus using the advanced nonlinear isotropic/kinematic hardening model and results of numerical analysis were compared to experimental results. In this research, the effect of length, angle of cylindrical shell and loading history on ratcheting behavior were investigated. baxsed on the results, it was found that bending moment plays a crucial role in waste of energy and increase in plastic deformations. Seen that due to the existence of bending moment in different cross section of oblique cylindrical shell there are more plastic deformation in comparison to normal cylindrical shell. Linear relation was observed between plastic energy and rate of plastic deformation in one step loading. Analyzing the loading history of cylindrical shell under combined loading, by the prior load with higher force amplitude retards the ratcheting behavior and plastic deformation with smaller force amplitude. Also, circular cutout effect on cylindrical shells under these kinds of loading has been studied and observed that creating of cutout increases the plastic deformation and it’s rate. Shells buckling investigation has been done with numerical method and observed that for oblique cylindrical shell with elliptical cutout, the buckling load reduces when width of cutout increases. Also, increasing length of the shell decreases the buckling load.