Al-Sn-Si　alloys　have　been　widely　used　as　bearing　alloys　in　automotive　engines.　In　those　alloys,　beta(Sn)　phase　serves　as　the　solid　lubricant　and　Si　particles　are　used　to　improve　the　hardness,　fatigue　resistance　as　well　as　seizure　resistance.　With　the　development　of　machinery,　bearing　alloys　with　higher　load-carrying　capacity　and　better　tribological　properties　are　demanded　to　meet　the　application　under　severe　conditions.　Adding　appropriate　Mg　to　the　Al-Sn-Si　alloy　can　effectively　optimize　the　tribological　properties.　In　this　paper,　the　microstructure,　mechanical　properties　and　tribological　properties　of　the　Al-12Sn-4Si-xMg　(x　=　0,　0.5,　1,　1.5,　all　in　wt.%)　alloys　were　studied.　The　Al-12Sn-4Si-1.5　Mg　alloy　had　the　smallest　grain　size　and　more　uniform　microstructure　than　other　specimens.　The　Al-12Sn-4Si-1.5　Mg　alloy　showed　significantly　better　wear　resistance　than　the　Al-12Sn-4Si　alloy　at　2　N-70　N.　The　volume　wear　rates　and　friction　coefficients　at　15　N-70　N　were　lower　than　those　at　2　N-8　N.　The　evolution　of　volume　wear　rate　and　friction　coefficient　with　load　was　related　to　the　evolution　of　tribolayer　with　load.　The　wear　mechanism　of　the　alloys　was　mainly　oxidation　wear,　adhesive　wear　and　fatigue　wear,　accompanied　with　abrasive　wear.　(c)　2022　The　Authors.　Published　by　Elsevier　B.V.This　is　an　open　access　article　under　the　CC　BY-NC-ND　license　(http://creativecommons.org/licenses/by-nc-nd/4.0/).