The catalytic performances of a new family of crystalline Re-Sb-O compounds SbRe2O6, SbOReO4.2H(2)O and Sb4Re2O13 in selective ammoxidation of isobutane (i-C4H10) to methacrylonitrile (MAN) have been studied and compared with those of a mechanical mixture of Sb2O3 + Re2O7, coprecipitated SbRe2Ox, Sb2O3-supported Re2O7, bulk Re oxides, and Sb oxides. SbRe2O6 efficiently catalyzed the i-C4H10 ammoxidation to MAN at 673 K with the good selectivity to MAN (44.9%) and to the sum of MAN + i-C4H8 (84.3%) at a steady-state conversion of 4.4%, while significantly no MAN activity was observed on the other catalysts. No structural change in the bulk and surface of SbRe2O6 after the i-C4H10 ammoxidation was observed by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and in situ confocal laser Raman microscopic spectroscopy (LRM). The good performance of SbRe2O6 may be ascribed to its specific crystal structure composed of alternate octahedral (Re2O6)3(-) and (SbO)(+) layers. It was found that the presence of NH3 was prerequisite to the C-H bond breaking Of i-C4H10, and the oxidation/dehydrogenation Of i-C4H10 never proceeded in the absence of NH3. The presence of NH3 was also prerequisite to maintain the crystal structure of SbRe2O6 Under the reaction conditions. Fourier transformed infrared (FT-IR) spectra showed that NHx species irreversibly adsorbed on the SbRe2O6 catalyst. The i-C4H10 ammoxidation proceeded on SbRe2O6 by a redox mechanism, in which the oxidative dehydrogenation of i-C4H10 to i-C4H8 was the rate-determining step. Increasing reaction temperature and decreasing GHSV did not give rise to increase in the formation of byproducts CO2 and acetonitrile. Thus the crystalline SbRe2O6 compound may be regarded to be a new promising catalyst for the ammoxidation of light alkanes.