Effects　of　trace　Ni,　P　or　Ce　element　additions　on　the　microstructure　and　the　properties　of　the　Sn3.0Ag0.5Cu　solder　alloy　were　investigated.　Results　show　that　single　adding　of　Ni,　P　or　Ce　has　little　influence　on　the　melting　temperature　of　the　Sn3.0Ag0.5Cu　solder　alloy.　P　addition　can　improve　the　wettability　of　the　solder,　i.e.　the　wetting　force　of　the　solder　is　increased,　and　the　wetting　time　is　decreased.　Single　adding　of　Ni　or　Ce　has　no　significant　effect　on　the　wettability　of　the　soldered　alloy　and　the　shear　strength　of　the　as-reflowed　soldered　joint,　but　can　remarkably　suppress　the　decrease　of　the　shear　strength　of　the　solder　joints　due　to　the　high-temperature　aging.　Besides,　P　addition　significantly　increases　the　oxidation　resistance　of　the　soldered　alloy,　but　rare　earth　Ce　addition　deteriorates　it.　The　property　change　of　the　Sn3.0Ag0.5　solder　are　attributed　to　the　change　of　the　microstructure　caused　by　trace　Ni,　P,　or　rare　earth　Ce　additions.