We introduced different amounts of Li+ ions into La1/3NbO3 with an A-site-deficient perovskite structure and determined crystal structures of the resultant oxides La1/3LixNbO3 (x = 0, 0.075, and 0.444). Reflections arising from superstructures appeared in their neutron powder diffraction patterns. Rietveld refinements revealed that the superstructures result from tilting of NbO6 octahedra and ordering of cations and vacancies at A sites. La1/3LixNbO3 varied from an insulator to a semiconductor with increasing x.