The formation of a solid solution containing the three elements V, Sb and Mo, which are key-elements in the design of light alkane oxidation catalysts, has been studied by incorporating molybdenum into the pure VSbO 4 compound as obtained in air at 700°C (V 3+0.28V 4+0.64□ 0.16Sb 5+0.92O 4). Monophasic compounds with a rutile-type structure have been obtained and characterized by X-ray diffraction, electron microscopy, Infrared Fourier transform, X-ray absorption and electron spin resonance spectroscopies. At low molybdenum content, Mo 6+ substitute V 4+ in the cationic-deficient structure. The charge balance is maintained by an increase of the cationic vacancy number. This leads to the formation of a solid solution corresponding to the formula V 3+0.28V 4+0.64-3 xMo 6+2 x□ 0.16+ xSb 5+0.92O 4 with 0< x<0.09. At higher molybdenum content, Mo 5+ are stabilized and substitute Sb 5+ in the rutile structure: V 3+0.28V 4+0.37Mo 6+0.18□ 0.25Mo 5+ySb 5+0.9- yO 4 with 0< y<0.06. At higher molybdenum content the rutile phase is no longer stable and two new phases are formed: Sb 2O 4 and a new mixed vanadium molybdenum antimonate.