[en] The interaction of indium oxide with antimony oxides during heating under various conditions has been studied. The results of this study indicate that two complex oxides In₂Sb₄O₉ and Insub(2-x)Sbsub(x)Osub(3+x) with a rutile-type structure are formed (for the latter compound, the homogeneity region is insignificant and x approximately 1). Some physico-chemical characteristics of the obtained phases are given. The derived compounds have been examined by chemical analysis, NGR-spectroscopy and differential thermal analysis