Abstract: Abstract：Maceral separation is the priority of improving the deep processing and utilization efficiency of coal resources on a basis of the characteristics difference of maceals. Based on fat coal from QianJiaying coal mine, using method under microscope observation, the paper studied the distribution and liberation characteristics, and determined the free fractional degree of macerals, and researched the maceral separation efficiency using density-based separation method under different crushing size. The distribution and liberation characteristics of maceral show that with the decrease in the size fraction, vitrinite content increases slowly first and then increase rapidly , while inertinite content decrease slowly first and then decreases rapidly; When coal crushing size comes to -0.074mm, the free fractional degree of vitrinite reaches 90.77%, that of inertinite reaches 61.78%, which indicates that vitrinite is easier to dissociate than inertinite. Maceral separation of coal samples under different crushing size demonstrates that vitrinite-rich concentrate with a vitrinite content 89.77% and vitrinite recovery 61.19% can be obtained from density-based separation with separation density 1.33kg/l for -0.074mm coal sample; Deeper crushing is needed if a increase of inertintie free fractional degree and reduction is wanted.