Effect　of　Er　content　on　the　microstructure,　texture　and　mechanical　properties　of　Al-Mg-Si-Mn　alloys　at　solid　solution　state　was　investigated　by　tensile　testing　at　room　temperature,　micro-hardness　test,　SEM/EDS　and　EBSD　analysis;　the　mechanism　of　effect　of　Er　was　also　explained.　The　experimental　results　showed　that　solid　solution　strengthening　treatment　at　540Cfor　30　min　could　obtain　the　highest　micro-hardness　and　the　tensile　strength.　Yield　strength　could　be　enhanced　and　the　elongation　decreased　with　the　increasing　of　Er　content.　Mn　and　Er　were　included　in　the　inter　metallic　compounds　that　were　not　solid　solution　treated.　As　to　the　alloy　with　0.2%　Er,　which　inhibited　re　crystallization　process　by　inter　metallic　compounds　containing　Er,　its　texture　was　Brass　structure;　and　for　the　alloy　with　0.4%　Er,　which　could　be　as　the　nucleation　sites　for　the　re　crystallization,　the　texture　of　the　deformation　state　was　weakened.