Abstract: In this paper, the texture of kerogen is studied, using x-ray diffraction to determine the aromaticity of kerogen.According to the x-ray diffraction spectra, the microcrystalline parameter of the kerogen is calculated. The study indicates that the aromaticity is related to the types of kerogen, and keeps good relationship with the H/C atomic ratio of kerogen. The microcrystalline parameter bears a direct relationship to the evolutionary level of the kerogen, i.e. the higher the maturity, the higher the value of the microcrystalline parameter. Thus, it opens a new way for the study on kerogen.