Young’s modulus and hardness of Cu6Sn5 intermetallic compounds (IMC) were measured by nanoindentation. The samples were prepared according to actual reflow soldering condition and service. The microstructure and chemical composition of the samples were characterized by scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX). With continuous stiffness measurement (CSM) technique and difference strain rates, continuous values of hardness and elastic modulus for Cu6Sn5, which belong to lead-free solder joints (Sn3.0Ag0.5Cu, Sn0.7Cu and Sn3.5Ag), were measured. The load, Young’s modulus and hardness-displacement curves were obtained. The creep stress exponents for Cu6Sn5 were determined by nanoindentation.