Abstract: Numerical simulations were performed on the photonic band gap (PBG) properties of the photonic crystal fibers(PCFs) possessing a clad with the cladding holes triangle-lattice distributed and a round fiber core using the full-vector plane-wave expansion method. Through the comparative analysis on the relationship of the PBG property and the structure parameters(cladding hole diameter dclh, cladding hole pitch and cladding hole filling ration f) between traditional(air-silica) and all-solid-state(nonair-silica) PCFs, a design of an all-solid-state PCF was given out which operates at the communication wavelength of 1 550 nm with the parameters dclh=1.0 m, =2.0 m and f=0.23 at the conditions of fiber core diameter dco=5.3 m and cladding hole material's refractive index nclh=1.65. Further numerical simulation shows that this resulting PCF has a gap width up to 43 nm.