Abstract: The enrichment characteristics of organic matters were determined by its petrology. The types and contents of macerals in Huadian oil shale were examined with 3 common microscope lighting conditions (transmitted light, reflected polarized light and reflected fluorescent light). Then two separation methods based on density difference were used to study liberation of organic mattes from minerals. A low degree of metamorphism was found for organic matters in Huadian oil shale. The macerals were dominated by bituminite accounting for 85.8%. The contents of vitrinite and inertinite were low. Closely integrated with minerals, the organic matters were formed as organic-mineral aggregates. It was difficult to separate the organic matters from minerals using physical methods. Both the weight loss and differential weight loss of samples with density < 1.40g/cm³ were lower than that of higher density from float-and-sink analysis. This was attributed to that a small amount of vitrinite and inertinite particles was enriched in low density product due to their less integration with mineral matter.