The effects of temperature on dispersion, mode effective area and nonlinearity of an ethanol-filled index-guiding hexagon photonic crystal fiber were investigated using the vectorial beam propagation method. The results indicate that temperature has a significant influence on dispersion at the wavelengths of flattened dispersion, the bandwidth of flattened dispersion increases with temperature increasing. At the short wavelengths of flattened dispersion, the temperature has greater influence on the dispersion and the dispersion becomes more flattened. The impact of temperature on the mode effective area and the nonlinearity is larger at long wavelengths than at short wavelengths of flattened dispersion. At a given wavelength of flattened dispersion, dispersion and nonlinearity increase with temperature increasing. The result provides theoretical reference for designing novel optical communication components or optical sensors.