The atom–vacancy ordering of cubic vanadium monoxide VO1.29, which has basis cubic structure B1 and structural vacancies in the metal sublattice, has been studied using the x-ray diffraction method. It has been shown that the formation of the tetragonal (space group I41/amd) ordered phase V52O64 of cubic vanadium monoxide VOy proceeds as a first-order phase transition through the disorder–order channel including 22 nonequivalent superstructure vectors of four stars {k10}, {k4}, {k3}, and {k2}. The distribution function of the vanadium atoms in the V52O64 tetragonal superstructure has been calculated.