In this thesis, a series of carbazole/ fluorene/ benzothiadiazole-containing PPVs system polymers was synthesized and the relationships between chemical structure design and thermal stability, optical properties, electro-chemical properties, and device performance are characterized. At first, we synthesized a novel carbazole/ fluorene containing monomer as a blue emitter, and copolymerized with a red emitter, MEHPPV. We also synthesized a MEHPPV homopolymer as comparison. We also synthesized a benzothiadiazole-containing monomer to copolymerize a tricopolymer with various ratios to obtain the relationships between chemical structure design and thermal stability, optical properties, electro-chemical properties or device performance.