Low　cycle　fatigue　tests　on　96.5Sn-3Ag-0.5Cu　solder　joints　were　carried　out　using　micro-uniaxial　fatigue　testing　system　at　25　with　different　dwell　time　(1-20　s)　and　different　strain　rates　(0.01-0.08　mm/s).　The　results　show　that　dwell　time　of　1-20　s　has　little　influence　on　fatigue　life　of　solder　joints　at　25.　With　the　increasing　of　strain　rates,　the　fatigue　life　of　solder　joints　reduced　gradually,　and　fracture　mode　was　transformed　from　ductile　fracture　to　brittle　fracture.　Fatigue　cracks　tended　to　initiate　around　the　solder/IMC　interfaces　at　the　edge　of　the　joints　with　different　loading　speeds,　and　then　propagated　within　the　solder　proximately　along　the　IMC　interfaces.　The　fracture　morphology　of　solder　joints　with　different　strain　rates　consisted　mainly　of　propagation　region　and　final　fracture　region.　©,　2015,　Hanjie　Xuebao/Transactions　of　the　China　Welding　Institution.　All　right　reserved.