The effects of temperature on dispersion, effective area and nonlinearity of an index- guiding hexagon photonic crystal fiber filled by ethanol are described by using the vectorial beam propagation method, and a nearly zero ultra flattened dispersion fiber is optimized design with the dispersion coefficients of 0 ± 0.5 ps/(nm · km) at the wavelength of 1.46 µm to 1.65 µm. The results indicate that increasing temperature could lead to increase dispersion and nonlinearity, but decrease the dispersion slope so as to flatten the dispersion. The result provides theoretical base for designing continuously tailoring dispersion optical communication components or optical sensing devices.