Abstract: An identification method of an integrated circuit chip of the present invention includes identifying a surface structure or an internal structure of an integrated circuit chip, generating a structural information set according to the surface structure or internal structure, converting the structural information set into an identification information set. The identification information set generated by the above-mentioned identification method can be stored in a digital file, and a chip manufacturer requires no visible information printed on an outer surface of the integrated circuit chip such that factory information of the integrated circuit chip can be concealed.