The　influence　of　the　preparation　methods　of　Co-Al　layered　double　hydroxides　(LDHs)　on　the　structural　and　catalytic　properties　of　Co-Al　mixed　oxides　for　benzene　total　oxidation　was　investigated.　Various　Co-Al　LDHs　were　synthesized　via　constant　pH　precipitation,　decreasing　pH　precipitation,　and　urea　homogeneous　precipitation.　The　synthesized　samples　were　characterized　by　using　N-2　physical　adsorption,　ICP,　XRD,　TG-DTA,　SEM,　and　H-2-TPR.　The　characterization　results　showed　that　calcination　of　Co-Al　LDHs　gave　rise　to　Co-Al　mixed　oxides　consisting　of　Co(Co,　Al)(2)O-4　spinel　as　the　main　phase,　which　showed　relatively　small　crystallite　size　and　high　specific　surface　area,　i.e.,　similar　to　12　nm,　90-100　m(2)　g　(cat)　(-1)　.　The　highest　catalytic　activity　was　obtained　on　the　Co-Al　mixed　oxide　prepared　by　decreasing　pH　precipitation,　followed　by　that　prepared　by　constant　pH　precipitation,　while　the　Co-Al　mixed　oxide　prepared　by　urea　homogeneous　precipitation　was　much　less　active.　The　activity　difference　can　be　related　to　the　different　reducibility　of　Co3+　species　in　Co(Co,　Al)(2)O-4　spinel.