Abstract: A squeezed high birefringence Photonic Crystal Fiber (PCF) with high negative flattened dispersion characteristics was proposed. In order to obtain the high birefringence characteristics, the cladding of PCF was made of squeezed triangular lattice and elliptical air holes. In order to improve the flexibility of controlling the dispersion, the core of PCF was added into a small defect air hole. The birefringence and dispersion characteristics were analyzed by super lattice method. The simulation results show that the designed PCF offers ultra flattened negative dispersion (-6677 psnm-1km-1) in a broad range of wavelengths from 1.3 m to 1.8 m, the birefringence can be reached the magnitude of 10-2 and the high birefringence can be reached 2.2110-2 at 1.55 m. Based on the high negative dispersion and high birefringence characteristic, PCF will be widely used in optical transmission system and optical fiber sensing.