Sn-Bi-In　low-temperature　solder　was　fabricated　by　adding　In　element　to　tin-bismuth　series　solder.　In　this　paper,　to　study　the　solders　with　melting　temperature　around　110°C　for　replacing　the　toxic　26Sn-54Bi-20Cd　alloy,　the　microstructures,　thermal　properties,　wettabilities　and　microhardness　of　solders　were　studied　respectively.　The　results　show　that　the　microstructure　of　Sn-Bi-In　solders　is　composed　of　BiIn2　matrix,　InSn4　and　Bi　phases,　and　transformed　to　Snrich　matrix,　Bi　and　InBi　phases　with　the　In　content　reduction.　In　addition,　the　melting　temperatures　of　solders　with　12wt%　In　content　are　around　101.5-103.1°C.　Wettability　is　affected　by　compositions　and　the　increase　of　Sn　content　to　50wt%　can　promote　the　spreading　of　solders.　Microhardness　can　be　increased　by　Bi　addition　and　In　reduction.　Based　on　these　properties　study,　50Sn-38Bi-12In　solder　is　comparable　to　26Sn-54Bi-20Cd　solder,　and　could　be　used　in　the　special　lowtemperature　welding.　©　2015　IEEE.