The purpose of this paper is to clarify the buckling strength, deformation capacity and strength inferiority of high-strength steel pipes by stub column tests and non-linear analysis. Pure compression is applied on three series of stub columns, two of them consist of pipes with different yield stress strength and the other consists of pipes which are annealed. The strength characteristics mentioned above are proved to be well explained by the non-dimentional parameter α_c, where α_c=E/σ_<yc>・t/D. Numerical analysis which takes both geometrical and material nonlinearity into account is applied using the axishell finite elements. It is shown that the results obtained by the analysis well explain the experimental test data. It is noted that the annealed pipes may have less strength and deformation capacity than the not-anneled pipes when the radius-thickness ratio is large.