Novel cross-linked polyphosphazenes with remendable capacity have been synthesized through the Diels-Alder reactions. Their structure and properties were characterized by NMR, FT-IR, GPC, DSC, TGA SEM, and polarizing microscope. The process of Diels-Alder reaction (D-A reaction) and retro-Diels-Alder reaction (retro-D-A reaction) have been investigated by FT-IR, UV, and DSC. The cross-linked polyphosphazenes exhibited remendable capability only need a thermal treatment when they were cut by blade, any other treatments such as additional monomer or catalyst, surface treatment or pressure were not needed. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013