A kind of elliptical structure photonic crystal fiber with diameter increasing air holes is proposed. In this structure all the circular air holes are arranged in six elliptical rings. And the diameter of each rings increase from the inner to the outer. Moreover, we have choose some air holes to coating the metal Au and filling the liquid of the purified water. Properties, just like the confinement loss, of these structures with different diameters of the holes and thickness of the gold layer are numerical analyzed by using the finite element method. Numerical results show that the resonance strength in x-direction is much stronger than in y-polarized direction, and filling the liquid and changing the thickness of the gold film can significantly increase the loss of core mode polarized in the x-polarized direction.