The tin whiskers spontaneously grew from the NdSn3 intermetallic compound(IMC) after exposure to ambient conditions.One such fine tin whisker with a diameter of about 600 nm was observed by transmission electron microscope(TEM).The results showed the whisker was a perfect β-Sn single-crystal without dislocations or low angle grain boundaries.The whisker growth axis was calculated as [111].There were interference fringes in the bright-field image of the tin whisker,which reflected the existence of growth stress in the whisker.A 15-18 nm native tin-oxide film on the tin whisker containing many crystal defects was also found.The new results are helpful in understanding the tin whisker growth mechanism.