In the present work, for the first time the CS2.5H0.5PW12O40/SBA-15 catalysts were prepared as highly efficient catalysts for the direct production of glutaric acid (GAC) via selective oxidation of cyclopentane-1,2-diol by using aqueous hydrogen peroxide as the green oxidant. The yield of GAC is higher than 88%. The fresh catalyst and the recovered ones were all characterized by XRD, FT-IR, Raman and P-31 MAS NMR to reveal the structure change during the reaction. XRD results revealed that the Cs2.5H0.5PW12O40/SBA-15 catalysts keep the crystalline structure of the as-prepared CS2.5H0.5PW12O40. And it is found that the structure of the Cs2.5H0.5PW12O40/SBA-15 catalysts was retained after the reaction, as determined by Raman, FT-IR and (31)p MAS NMR. The new CS2.5H0.5PW12O40/SBA-15 catalyst can be easily recycled after reaction and can be reused six times, indicating its excellent stability. (C) 2008 Elsevier B.V. All rights reserved.