Effects　of　solution　temperature　on　microstructure　and　corrosion　resistance　of　hyper　duplex　stainless　steel　contained　0.51%　and　0.72%　N　were　investigated.　And　the　corrosion　resistance　of　hyper　duplex　stainless　steel　compared　with　super　duplex　stailess　2906　were　analyzed.　The　results　show　that　hyper　duplex　stainless　steel　containing　0.51%　N　is　composed　of　ferrite　phase　and　austenite　phase　with　the　solution　treatment　temperature　in　1170~1220°C.　γ2　precipitates　can　be　observed　in　hyper　duplex　stainless　steel　with　0.72%　N　at　1170°C.　As　the　solution　treatment　temperature　increased　to　1200°C　and　to　1220°C,　γ2　precipitates　are　dissolved.　Hyper　duplex　stainless　steel　containing　0.51%　N　and　0.72%　N　exhibits　excellent　corrosion　resistance　with　the　solution　treatment　temperature　of　1200°C.　γ2　precipitates　are　susceptible　to　corrosion.　The　corrosion　resistance　of　hyper　duplex　stainless　steel　with　0.72%　N　γ2　is　superiorto　that　of　ones　with　0.51%　N,　Corrosion　resistance　of　2906　steel　is　the　worst.