The　precipitation　and　age　hardening　response　of　the　solid-soluted　Mg-10Gd-1Er-1Zn-0.6Zr　(wt.%)　alloy　performed　by　water-quenching　(QC),　air-cooling　(AC)　and　furnace-cooling　(FC)　in　terms　of　the　volume　fraction　of　precipitates　and　tensile　properties　were　investigated　in　present　paper.　Results　indicated　the　solid-soluted　alloy　contained　stacking　faults　(SFs)　and　long　period　stacking　ordered　(LPSO)　phase　on　the　basal　planes　regardless　of　the　cooling　rate,　but　a　larger　volume　fraction　of　the　LPSO　phase　was　formed　with　decreasing　in　the　cooling　rate.　After　aging,　beta＇　and　beta(1)　phases　precipitated　on　the　prismatic　planes,　and　their　number　density　decreased　but　mean　particle　size　increased　with　decreasing　in　the　cooling　rate.　The　solid-soluted　alloys　(QC,　AC　and　FC　samples)　showed　no　apparent　difference　in　yield　strength　(YS),　but　their　correspondent　peak-aged　alloys　exhibited　sharp　difference　in　hardening　response.　The　strongest　hardening　response　took　place　in　the　QC　sample　and　showed　82　MPa　enhancement　in　YS,　which　was　much　larger　than　that　of　AC　(+26　MPa)　and　FC　samples　(+5　MPa).　The　reason　lies　in　that　the　higher　cooling　rate　promotes　the　precipitation　and　reduces　the　average　size　of　beta＇　precipitate.　A　novel　cooling-rate　controlled　precipitation　model　with　respect　to　the　correlation　of　precipitates　on　basal　and　prismatic　planes　was　established.　From　this　model,　the　basal　precipitates　showed　a　restrictive　effect　on　the　growth　and/or　coarsening　of　beta＇　precipitate,　and　composite　precipitates　containing　the　beta＇　phase　with　fine　size　as　well　as　high　area-number　density　and　lower　volume　fraction　of　the　LPSO　phase　are　preferred　to　strengthen　the　Mg-10Gd-1Er-1Zn-0.6Zr　alloy.　(C)　2020　Chongqing　University.　Publishing　services　provided　by　Elsevier　B.V.　on　behalf　of　KeAi　Communications　Co.　Ltd.