Novel polygonal Nb2O5 platelets have been generated by a simple solvothermal technique. Then, the polygonal Nb2O5 nanoflakes as a template react chemically with NH3 and H2S to generate polygonal Nb3.49N4.56O0.44 nanoflakes and the polygonal NbS2-Nb2O5 nanoflakes. Under optimal conversion conditions. the final geometry features of polygonal Nb3.49N4.56O0.44 nanoflakes and the polygonal NbS2-Nb2O5 nanoflakes are predetermined by the size and morphology of the Nb2O5 platelets. TEM observation has showed that the Nb2O5 nanoplatelets and Nb3.49N4.56O0.44 nanoflakes consist of well-crystallized single crystals, the polygonal NbS2-Nb2O5 nanoflakes are composed of phases of mixed oxide and sulphide. These new polygonal plate-like nanostructures are important for understanding nanostructure processing. (C) 2008 Elsevier B.V. All rights reserved.