Urchin-like　Co3O4　has　successfully　grown　directly　on　ITO　glass　and　sensor　ceramic　substrate　through　hydrothermal　reaction　followed　by　calcination.　The　combined　characterizations　of　X-ray　diffraction　(XRD)　patterns,　nitrogen　adsorption-desorption　and　scanning　electron　microscopy　(SEM)　indicate　that　the　as-prepared　product　possesses　good　crystallinity,　large　specific　surface　area　and　urchin-like　morphology　which　is　greatly　influenced　by　the　reaction　additives.　The　sensor　with　urchin-like　Co3O4　growing　directly　on　ceramic　sensor　tube　exhibits　higher　response　sensitivity　than　the　sensors　fabricated　with　other　morphological　Co3O4　or　by　traditional　coating　method.(C)　2016　Elsevier　B.　V.　All　rights　reserved.