When polycrystalline metals are subjected to inelastic deformation, inhomogeneous deformation is induced in the individual crystal grains, In the present paper, the effects of temperature and loading type on this inhomogeneous deformation with plastic strain are examined experimentally using aluminium sheet specimens with coarse crystal grains. It is shown that for the uniaxial tension at room temperature the strain at the inside of grain is slightly larger than that at the grain boundary, while for the creep test at the temperature of 175°C the strain at the grain boundary becomes dominant. The surface roughness developments for these cases are closely related to such a deformation behaviour at the grain and the grain boundary.