In this paper, the surface microstructures of suckers and endoskeletons,which collected from seven species in Cephalopods, were observed by the scanning electron microscope. Methods: Three samples from each structure were fixed with 2.5% pentanediol, and then, cut the suckers, endoskeletons separately into 0.5 cm x 0.5 cm of small pieces. All small pieces should be dehydrated with 30%,70%,95% and 100% alcohol before observed by the scanning electron microscope. Samples would be measured and taken pictures after them were observed. Results:The results showed that suckers of Octopus ocellatus, O. vulgaris and O. variabilis (belong to Octopodidae) had no teeth. There are teeth, on the suckers surface in populations of Sepia japonica and S. esculenta (belong to Sepiidae), and their sucker with cuticular ring. While, their teeth structures are difference in different species. However, in population of S. pharaonis, the suckers with smoothy cuticular ring and have no teeth. While, in the population of Uroteuthis chinensis, their suckers with cuticular rings have no teeth. In those cuttlefishes observed by scanning electron microscopy, all the endoskeletons surfaces (back and ventral) are composed of aragonite and small spherical particles, but the shape of aragonite and the arrangement of the spheric particles are different in different species. Conclusion: Those differences are enough to classify Cephalopods species as auxiliary characters.