Ethylene　elimination　can　effectively　inhibit　the　rapid　aging　of　fruits　and　vegetables　in　storage　and　transportation.　Improving　the　low-temperature　activity,　moisture　resistance,　and　stability　of　Pt　based　catalysts　is　a　challenge　for　catalytic　oxidation　of　ethylene　which　is　an　effective　elimination　method.　Herein,　we　constructed　ultrasmall　MnOx　cluster　(＜　1　nm)　on　Pt　particles　via　an　alloy　in　situ　transformation　strategy,　which　created　a　large　number　of　MnOx/Pt　interfaces.　Among　all　of　the　samples,　1.89Pt(2.20)Mn/TiO2　showed　the　highest　catalytic　activity　in　the　oxidation　of　ethylene　at　a　space　velocity　of　20,000　mL/(g　h):　T-50%　=　34　degrees　C　and　T-90%　=　43　degrees　C,　specific　reaction　rate　at　35　degrees　C　=　33.0　mu　m　degrees　l/(g(Pt)　s),　and　turnover　frequency　at　35　degrees　C　=　6.5　x　10(-3)　s(-1).　In　addition,　Pt2.20Mn/TiO2　also　exhibited　better　water　resistance　and　stability　than　Pt/TiO2.　The　results　of　XPS,　H2O-TPD,　C2H4-TPD,　in　situ　DRIFTS,　and　(H2O)-O-18　isotopic　tracing　characterization　revealed　that　the　MnOx/Pt　interfacial　sites　accelerated　desorption　of　CO2　and　enhanced　the　activation　of　surface　active　oxygen　species　(O-2　to　O-2(2-)).　Meanwhile,　the　numerous　interfaces　provide　more　active　sites　for　ethylene　adsorption　and　activation,　reducing　the　inhibitory　effect　of　adsorbed　water　on　ethylene　adsorption.　It　was　concluded　that　the　prohibited　CO2　adsorption,　and　increased　adsorbed　oxygen　species　were　responsible　for　the　excellent　catalytic　performance　and　good　stability　of　1.89Pt(2.20)Mn/TiO2,　while　the　more　active　sites　for　ethylene　adsorption　and　activation　were　responsible　for　the　good　water　resistance　of　1.89Pt(2.20)Mn/TiO2.