AlCoCrFeNiTi0.5　high-entropy　alloy　was　prepared　by　water　cooled　copper　crucible　vacuum　induction　levitation　melting,　and　then　the　oxidation　behavior　of　the　alloy　was　studied　at　800,　900,　1000　and　1100　degrees　C.　The　ingredients　and　morphology　of　oxide　films　were　analyzed　by　XRD,　SEM　and　EDS,　and　the　oxidation　mechanism　of　the　alloy　was　explored.　The　results　show　that　the　oxidation　kinetics　curve　of　the　alloy　obeys　six　power　of　parabolic　law　at　800　and　900　degrees　C,　while　it　follows　the　quadruplicate　parabolic　law　at　1000　and　1100　degrees　C.　The　alloy　exhibits　excellent　oxidation　resistance　and　it　is　of　antioxidant　level　at　800,　900　and　1100　degrees　C　and　completely　of　antioxidant　level　at　1000　degrees　C.　Oxidation　occurs　mainly　in　interdendritic　and　eutectic　area,　and　the　oxidation　products　are　mainly　TiO2,　Fe2TiO5　and　FeCr2O4,　reuniting　in　an　island　morphology,　which　flake　remarkably　at　1100　degrees　C.　While　the　oxidation　products　in　dendritic　area　are　simple,　which　are　diffusely　distributed　Al2O3　particles　below　1000　degrees　C,　and　dense　Al2O3　layer　at　1100　degrees　C.　Both　phase　structure　and　hardness　of　the　alloy　are　stable　after　high-temperature　oxidation.