In　this　paper,　the　damage　effect　was　considered　into　the　impact　process　of　lead-free　solder　specimens.　Based　on　the　experimental　data,　the　modified　rate-dependent　Johnson-Cook　model　for　the　Sn3.0Ag0.5Cu　and　Sn3.5Ag　lead-free　solders　were　derived.　The　stress-strain　curves　obtained　from　the　modified　Johnson-Cook　material　models　and　the　experiments　agreed　quite　well　with　each　other.　It　indicates　that　presented　modified　Johnson-Cook　models　are　suitable　to　describe　the　dynamic　behavior　of　the　two　lead-free　solder　materials.