Composite　oxide　nanoparticles　are　promising　candidates　for　catalytic　applications　to　reduce　the　usage　of　expensive　noble　metals.　However,　the　associated　inferior　low-temperature　activity　imposes　major　challenges　on　the　rational　design　and　modulation　of　compositions.　Herein,　we　reported　for　the　first　time　the　successful　synthesis　of　Co3O4-In2O3　composite　oxides　with　the　nanoparticle　size　of　10-20　nm　for　methane　combustion　via　a　modified　precipitation　method　adopting　the　organic　base　N-butylamine　as　a　precipitator　to　eliminate　the　negative　effects　resulting　from　conventional　inorganic　base　precipitators.　The　doped　In3+　would　first　occupy　octahedral　sites　of　the　spinel　Co3O4　and　then　tetrahedral　sites,　resulting　in　the　increase　of　Co2+　ratio　on　the　surface　when　the　doped　molar　ratio　(nIn)　was　0-0.2　and　decrease　with　excessive　doping　(nIn　of　0.2-0.4).　The　increment　of　Co2+　ratio　was　essential　for　the　formation　of　abundant　reactive　oxygen　species,　improvement　of　reducibility,　and　optimization　of　surface　acidity,　which　synergistically　contributed　to　superior　catalytic　activity　with　a　T99　of　395　°C.　The　catalytic　activity　of　the　tailored　Co-In-0.2　nanocatalyst　is　among　the　best　of　the　state-of-the-art　Co-based　catalysts;　meanwhile,　it　also　exhibits　excellent　stability　and　water　resistance.　Copyright　©　2020　American　Chemical　Society.