By employing a full-vector finite-element method and anisotropic perfectly matched layers, a novel rectangular-hole photonic crystal fiber is fully investigated and a method to achieve high birefringence of the photonic crystal fiber is proposed. Simulation results show that birefringence property of the rectangular-hole photonic crystal fibers is almost the same as the elliptical-hole photonic crystal fiber which can achieve the high birefringence up to the order of 0.01. Both the rectangular-hole photonic crystal fiber and the elliptical-hole photonic crystal fiber have the similar properties such as the mode profile, birefringence, confinement loss and so on.