Intermetallic　compounds　(IMCs)　that　grow　on　the　interface　between　the　solder　alloy　and　its　bonding　pads　play　a　crucial　role　in　the　reliability　of　solder　joints.　It　has　been　identified　that　the　cracking　around　the　IMC　layer　is　the　primary　failure　mode　in　lead-free　solder　joints.　Therefore　the　mechanical　behavior　of　the　IMC　has　attracted　great　attentions.　In　this　paper,　mechanical　properties　of　two　kinds　of　intermetallics,　Cu6Sn5　and　Cu3Sn,　which　are　two　major　species　of　IMCs　in　lead-free　solder　with　Cu　pad　metallization,　are　collected　and　discussed.　The　measurements　on　Young＇s　modulus　and　hardness　of　Cu6Sn5　and　Cu3Sn　show　a　great　diversity　among　different　researchers＇　work.　Although　the　strength　of　IMC　exhibits　diversity,　some　common　trends　emerge.　Tensile　and　shear　strength　if　the　IMC　decrease　with　the　increasing　of　the　thickness　of　interfacial　intermetallic　layer.