FeCoCrNiB0.5　high-entropy　alloy　coating　was　prepared　on　Q235　steel　substrate　by　laser　cladding.　Effects　of　aging　on　microstructure　and　hardness　of　the　coating　were　investigated　by　XRD,　SEM　and　Vichers　hardness　tester.　The　results　show　that　the　coating　is　composed　of　single　FCC　solid　solution　and　M2B　phases,　and　the　structure　of　coating　has　good　stability　when　it　aged　at　high　temperature.　When　aged　at　800　℃　and　900　℃,　there　are　lots　of　M2B　phase　with　granular　shape　precipitated　from　the　dendrites.　However,　when　aged　at　1000　℃,　the　M2B　phase　in　the　dentrite　of　coating　grows　up　significantly,　and　the　dendritic　microstructures　in　the　coating　disappear.　The　microhardness　of　the　as-clad　coating　is　447　HV0.2,　and　further　decreases　gradually　with　aging　temperature　increasing.　©,　2015,　Chinese　Mechanical　Engineering　Society　of　Heat　Treatment.　All　right　reserved.