Orientation dependence of dislocation structure in surface grains of pure aluminium deformed in tension was investigated and compared with that in bulk grains. At a medium strain level, i.e., 0.18, dislocation cell structure is dominated in [100]–[100] surface grain of pure aluminium, which follows the same rule with its bulk counterpart. However, [110]–[110], [111]–[111] and [110]–[111] surface grains, which also characterized with typical dislocation cells, do not follow the bulk orientation-dependent dislocation evolution rule (dislocation cell block is evident in these orientated bulk grains). The orientation-dependent rule of dislocation structure in surface grains of pure aluminium is discussed in terms of slip system, slip activity and surface slip trace. In addition, hardening behaviour in surface region of pure aluminium are briefly addressed and compared with that in the bulk region. The findings are of importance for the plastic deformation of miniature components, where the majority is surface grains. • Studied orientation dependence rule of dislocation structure in surface grains of pure aluminium • Surface slip traces and the beneath dislocation structures of different orientated grains are compared • The findings are of great importance for the deformation of miniature metallic materials [ABSTRACT FROM AUTHOR]