Because of enrichment of kerogen in the beneficiation process, oil shale may be used more effectively in both oil production and power generation. The float and sink tests were carried out to separate the raw oil shale samples into a series of fractions according to density first. Density distribution of Longkou oil shale in China indicated the ash content of oil shale with different density fractions increased with the increasing of density fraction, and the inorganic minerals composition of oil shale was mainly quartz, kaolinite, montmorillonite, calcite, analcime, dolomite, and pyrite. Comprehensive considering the results of XRF, XRD, and optical microscopy of Longkou oil shale in each density fraction all indicated there was high content of kerogen in low density fraction of oil shale. Although it is difficult to separate pure kerogen from oil shale, relative beneficiation of kerogen from raw oil shale could be realized using the gravity separation method. After the separation of raw oil shale using a dense medium cyclone, separation products can be used in different ways according to their quality, the kerogen-rich products can be used for retorting to produce shale oil, and the kerogen-poor products can be used for power generation or temporarily sealed.