Microstructure　and　mechanical　properties　at　room　temperature　of　Zn-22Al　based　alloy　extruded　tube　were　studied　under　different　heat　treatment　conditions.　The　results　show　that　the　microstructure　of　as-extruded　tube　consists　of　α　and　η　two　phases.　After　subjected　to　superplastic　treatment,　the　alloy　shows　fine　equiaxed,　together　with　some　oriented　small　particles.　The　hardness,　elongation　and　ultimate　tensile　strength　of　the　extruded　tube　annealed　at　200　℃　for　9　h　are　62.52　HV0.05,　27.20%,　and　233　MPa,　respectively,　while　the　hardness,　elongation　and　ultimate　tensile　strength　of　the　extruded　tube　are　41.03　HV0.05,　139.47%,　and　98　MPa,　respectively,　when　quenched　at　320　℃　for　6　h　and　tempered　at　250　℃　for　0.5　h.　©,　2015,　Chinese　Mechanical　Engineering　Society　of　Heat　Treatment.　All　right　reserved.