Abstract: The mode field of a kind of photonic crystal fiber structure with hexagon symmetry hole cladding was analyzed by multipole method, and the effective refractive indexes of base mode at different wave lengths were obtained. The characteristics of this photonic crystal fiber grating were computed and simulated by coupled-mode method and transmission matrix method, and the difference between conventional fiber grating and photonic crystal fiber grating on their reflection spectrum was compared. The paper also analyzed the changes of photonic crystal fiber grating resonant wavelength with the structural change of photonic crystal fiber. Photonic crystal fiber grating has shorter resonant wavelength with increased radius of photonic crystal fiber pillars. Photonic crystal fiber grating has longer resonant wavelength with increased layers of photonic crystal fiber pillars but same radius.