Basing on scalar approximation the dispersion property of photonic crystal fibers (PCF) with lower air filling fraction are investigated by an effective index approach in this paper. It is found that the dispersion property of PCF can be modulated effectively by changing the pitch and the air hole size in PCF cladding. PCF can be designed not only with less than 1.27 μm zero-dispersion wavelength but also with two zero-dispersion wavelengths at the wavelength of optical communication. PCF with closing to zero and flattened chromatic dispersion in wavelength division multiplexing waveband of optical communication can also be obtained. The designed PCF has absolute value less than 2.0 ps·km-1·nm-1 in dispersion coefficient D and absolute value less than 0.02 ps·km-1·nm-2 in dispersion slope D′ at the wavelengths from 1.2 μm to 1.7 μm.