A PEPA-containing benzoxazine (PEPA-Bz) was synthesized from phenol, aniline and PEPA derivative. The structure of target compound was confirmed by fourier transform infrared spectroscopy (FT-IR) and 1H nuclear magnetic resonance spectroscopy (1H NMR). And the properties of its homopolymer and its copolymer with bisphenol-based benzoxazine(Ba) were investigated. Thermal gravimetric analysis (TGA) showed that PEPA-containing polybenzoxazine has good thermal stability and char formation. The temperature at 5% weight loss is 235℃, the char yield ratio is 53% at 700℃and the LOI is 38.7. FT-IR and TGA were utilized to investigate the ring-opening copolymerization behavior of PEPA-Bz and Ba and their thermal properties, respectively. The results shows that the Flame retardant properties and char yield of the copolymer were both better than the homopolymer of Ba.