Abstract: The uniaxis tension and pure torsional tests in addition with torsional fatigue tests were conducted on 63Sn-37Pb and Sn-0.7Cu. The results show that the stress-strain relationship,yield stress,shear yield stress,tensile strength,shear strength of the solders have strong strain rate-dependence. But the elastic modulus and shear modulus do not have apparent strain rate dependent effect. The two solders belong to shear-type fracture materials,and the cyclic softening effect occurs under cyclic loading conditions.