Borocarbonitrides　(BCNs)　have　emerged　as　highly　selective　catalysts　for　the　oxidative　dehydrogenation　(ODH)　reaction.　However,　there　is　a　lack　of　in-depth　understanding　of　the　catalytic　mechanism　over　BCN　catalysts　due　to　the　complexity　of　the　surface　oxygen　functional　groups.　Here,　BCN　nanotubes　with　multiple　active　sites　are　synthesized　for　oxygen-assisted　methanol　conversion　reaction.　The　catalyst　shows　a　notable　activity　improvement　for　methanol　conversion　(29%)　with　excellent　selectivity　to　formaldehyde　(54%).　Kinetic　measurements　indicate　that　carboxylic　acid　groups　on　BCN　are　responsible　for　the　formation　of　dimethyl　ether,　while　the　redox　catalysis　to　formaldehyde　occurs　on　both　ketonic　carbonyl　and　boron　hydroxyl　(B-OH)　sites.　The　ODH　reaction　pathway　on　the　B-OH　site　is　further　revealed　by　in　situ　infrared,　x-ray　absorption　spectra,　and　density　functional　theory.　The　present　work　provides　physical-chemical　insights　into　the　functional　mechanism　of　BCN　catalysts,　paving　the　way　for　further　development　of　the　underexplored　nonmetallic　catalytic　systems.