Six fluorine-containing, mix-substituted phosphazene-based branched benzoxazine monomers with a low melting point were successfully prepared and their chemical structures were verified by 1 H, 13 C, 31 P and 19 F nuclear magnetic resonance (NMR). These branched benzoxazine resins underwent thermal ring-opening polymerization to form cured polymers with high thermal stability both in N 2 atmosphere and in air. The co-substituents, both m-CF 3 PhOH and p-CF 3 PhOH, imposed significant effects on processing, thermal, and surface properties of corresponding polybenzoxazines. Non-isothermal differential scanning calorimetry (DSC) under diverse heating rates was adopted to investigate the curing kinetics and determine the activation energy of polymerization. DSC results indicate that the m-CF 3 PhO-/p-CF 3 PhO-groups have the potential to lower ring-opening polymerization temperature. Glass transition temperatures (T g s) of polybenzoxazines derived from p-CF 3 PhOH are higher than that of polymers derived from m-CF 3 PhOH due to different steric hindrance and crosslinking density. More interesting, all polybenzoxazines show relatively high dielectric constant but exhibit low dielectric loss at ambient temperature.