In　the　present　work,　the　effect　of　Ni　doping　on　the　microstructures　and　properties　of　Zn-20Sn　high　temperature　lead-free　solder　has　been　investigated.　Interestingly,　Ni　was　present　as　the　form　of　Ni-Zn　compounds　in　the　microstructure　of　Zn-20Sn-xNi　alloy.　When　the　Ni-doping　amount　was　0.2　similar　to　0.4wt.%,　the　presence　of　d　phase　was　found,　and　when　the　doping　amoun　was　0.8wt.%,　the　presence　of　delta　phase　was　observed.　With　the　increase　of　Ni　content,　the　liquidus　temperature　increased　but　the　solidus　temperature　did　not　change　obviously.　In　addition,　the　microhardness　and　electrical　resistivities　of　Zn-20Sn-xNi　solder　increased　gradually.　And　the　spreading　area　and　shear　strength　increased　firstly　but　decreased　afterwards.　When　the　content　of　Ni　was　0.4wt.%,　the　spreading　area　and　shear　strength　of　solder　reached　to　be　maximum.　After　the　addition　of　0.4　wt.%　Ni,　the　microstructure　of　the　interfacial　intermetallic　compound　(IMC)　layer　of　the　interface　didn＇t　change,　but　the　total　thickness　of　the　IMC　layer　reduced.　The　delta-phase　was　embedded　in　the　grain　boundary　of　epsilon-CuZn5,　which　hindered　the　diffusion　of　atoms.　The　thickness　of　IMC　layer　at　the　interface　reduced,　which　led　to　the　improvement　of　the　shear　strength　of　the　interface.