The　evolution　of　mechanical　properties　and　microstructure　of　Al-5.7Mg-0.7Mn-0.1Zr-0.2Er　alloy　after　different　annealing　processes　were　studied　by　means　of　hardness　test,　OM　and　SEM.　The　annealing　processes　are　annealing　at　75-450　degrees　C　for　1　h　and　annealing　at　75,　150,　200,　250,　275,　300,　400,　470　degrees　C　for　0.5　to　100　h.　The　result　shows　that　annealing　temperature　has　a　greater　effect　on　mechanical　properties　and　microstructure　of　the　alloy　than　annealing　time　dose.　Annealing　for　1　h,　there　is　few　evolution　on　the　tested　alloy　at　annealing　temperature　75　degrees　C.　The　hardness　of　the　alloy　decreases　slowly　when　the　annealing　temperature　is　increased　from　125　to　250　degrees　C,　but　the　corrosion　resistance　is　low.　A　great　change　occurs　when　the　alloy　is　annealed　from　250　to　275　degrees　C,　i.e.　the　hardness　rapidly　decreased　by　28%,　while　the　corrosion　resistance　increased　remarkably.　The　hardness　of　the　tested　alloy　becomes　stale　after　annealing　above　275　degrees　C.　After　annealing　for　different　time,　most　evolution　of　mechanical　properties　and　microstructure　complete　within　0.5　h　at　any　annealing　temperatures;　annealing　under　200　degrees　C　or　above　275　degrees　C,　there　is　few　distinction　after　annealing　for　0.5　and　100　h.　therefore,　the　hardness　decrease　continuously　with　annealing　time　prolonging　in　the　range　of　200-275　degrees　C,　and　the　greatest　decrease　of　the　alloy　appears　at　250　degrees　C.　The　hardness　HV　of　the　alloy　with　different　annealing　process　is　no　less　than　850　MPa.