[en] The influence of the structure state formed under low temperature deformation (rolling with different reductions at 20 K) upon the superconducting characteristics of Nb single crystals (001) [110] is studied. The T_c variations with growing reductions σ reflect the stages of the defect structure evolution, in particular, the initial formation of regions of localized plastic flow, the change-over to a uniform dislocation distribution and the onset of rotational plasticity. Complex nonmonotonous changes are revealed for T_c, H_c2 and ρ_n on removal of the surface layers of deformed single crystals. The reasons for the effects observed are discussed