The phase composition of the mixed oxides, series LiMe x V2−x O4, where Me=Zn, Mg, was studied using X-ray analysis. The minor phases present in the investigated samples together with the basic spinel phase were determined as Li3VO4 and Zn2V2O7 or Mg2V2O7 respectively. Their presence is caused by the tendency of tetravalent vanadium ions to the disproportionation. For the compositionsx=0·375 were determined the quantitative phase compositions. The lattice constant of the spinel phase is linearly changing according to Vegard's rule, for the zinc series in the range 0≦x≦0·375 and for the magnesium series in the range 0≦xs≦0·25. Further substitution in magnesium series caused tetragonal deformation of the cubic spinel lattice.