A high birefringence and low loss of index-guiding photonic crystal fiber (PCF) is proposed and compared to other structures using the finite element method. The proposed structure is composed of a cladding with modifying elliptical air holes and a core of solid silica surrounded with two half-size air holes. Numerical results confirm that the proposed structure at the excitation wavelength of λ= 1550 nm provides extremely high birefringence (~2.085×10-2) and ultralow confinement loss (<1.63×10-5dB/km). The merit of the designed PCFs is that the high birefringence and low confinement loss can be easily achieved by reducing two air holes which are near the fiber core.