Abstract: Distribution of creep strain and stress of SnAgCu-CNT lap shear solder was studied under conditions of 125- -40℃ by means of finite element method(FEM).The results show that obvious shearing deformation is found on the lap solder after 4 thermal cycles, then is the visible displacement on the upper and lower surfaces. Maximum equivalent creep strain lies in the middle of length orientation of solder-pad surfaces, while minimum strain lies in the center of solder.FEM results coincide well with experiment results. The curve of equivalent creep strain and stress versus time in the node of maximum equivalent creep strain exhibit apparent periodicity and build-up effect.