Photonic crystal fiber (PCFs) offer new possibilities of realizing highly birefringence fibers due to a higher intrinsic index contrast compared to conventional fibers. Here, based on general section structure of PCFs, we take some mend in the core configuration, and achieve highly birefringence effect. A elliptic air hole and its inscribed circular high refractive material form the core of PCFs together. Especially to mention, they are being tangent at two points. By optimally selecting parameters, the effective refractive index difference between two orthogonal directions neff can reach the magnitude of 10-2. After numerical calculation, we find that increase the size of circular solid core, or long axe size of elliptic air hole, birefringence parameter of modal field can become more highly. Moreover, by matching structure parameters appropriately, the modal field diameters can be equivalent in the two orthogonal directions. A Gaussian modal field with highly birefringence character can be acquired.