Abstract: The large-scale thin-walled cylindrical shells used in the chemical or electric power engineering are always located some beams to support attached equipment because of the technology requirement. Consequently, the cylinder wall is subjected to partial axial compression from the beam. In the consideration of circumferential weld imperfection, a great amount of nonlinear numerical analyses are conducted to investigate the stability of the cylindrical shells when the cylinders are subjected to partial axial compression with the loading subtended angle being less than 10°. The research shows that the circumferential weld imperfection significantly influences the buckling bearing capacity of the cylinder subjected to partial axial compression. When the circumferential weld is located on the height where the maximum inward radial displacement occurs in the post buckling mode of the perfect cylinder, the imperfection causes the most unfavorable influence. The more significant amplitude of the weld imperfection will reduce the buckling bearing capacity of the cylinder, but the amplitude has little influence on the post buckling performance. The interaction between neighboring weld imperfection slightly increases the buckling bearing capacity of the cylinder. Based on a great many numerical computation results, the design recommendation is suggested with the varying imperfection amplitude and the ratio of radius against shell wall.