As　traditional　lead-based　solders　are　banned　and　replaced　by　lead-free　solders,　the　drop　impact　reliability　is　becoming　increasingly　crucial　because　there　is　little　understanding　of　mechanical　behaviors　of　these　lead-free　solders　at　high　strain　rates.　In　this　paper　mechanical　properties　of　one　lead-based　solder,　Sn37Pb,　and　two　lead-free　solders,　Sn3.5Ag　and　Sn3.0Ag0.5Cu,　were　investigated　at　strain　rates　that　ranged　from　600　s(-1)　to　2200　s(-1)　by　the　split　Hopkinson　pressure　and　tensile　bar　technique.　At　high　strain　rates,　tensile　strengths　of　lead-free　solders　are　about　1.5　times　greater　than　that　of　the　Sn37Pb　solder,　and　also　their　ductility　are　significantly　greater　than　that　of　the　Sn37Pb.　Based　on　the　experimental　data,　strain　rate　dependent　Johnson-Cook　models　for　the　three　solders　were　derived　and　employed　to　predict　behaviors　of　solder　joints　in　a　board　level　electronic　package　subjected　to　standard　drop　impact　load.　Results　indicate　that　for　the　drop　impact　analysis　of　lead-free　solder　joints,　the　strain　rate　effect　must　be　considered　and　rate-dependent　material　models　(if　lead-free　solders　are　indispensable.　[DOI:　10.1115/1.3168600]