Polyfluorenes with spiro structure chains were synthesized. Dihydroanthracene containing polyfluorene derivatives showed nearly the same optical properties as polydialkylfluorenes, however, the polymer exhibited greatly enhanced thermal properties followed by reduced harmful aggregate formation. The photoluminescence emission of the polymer film showed pure blue emission even after annealing at 200 ℃ for 15 hours in air. Electroluminescence spectrum also showed high color purity. Triphenylamine containing polyfluorene derivatives were also synthesized. The polymer showed enhanced thermal properties as well as increased HOMO energy level which could improve the hole injecting and transporting properties.