The electronic structure of eleven crystalline nickel oxides was investigated by band theory - CNDO method. Both the band and local properties of the electronic structure were calculated and were used for the description of chemical bonding in Ni(II) (NiO, Li₂NiO₂, Na₂NiO₂, K₂NiO₂, BaNiO₂, La₂NiO₄), Ni(III) (LiNiO₂, NaNiO₂, LaNiO₃) and Ni(IV) (BaNiO₃) compounds.