It has been established that the fine grinding of brown coal, lead to changes in its functional group composition, namely the reduction of carboxyl, carbonyl and aliphatic groups. Mechanical influences on coal simultaneously with a change in the total soluble fractions changed their composition and structure compared with the fractions of the original coal. Data obtained by hydrogenation show that the increased yield of liquid products by 10% and the depth of the transformation of the organic mass of coal by about 10-20%. Lowering the temperature of the autoclave hydrogenation led to an increase in the degree of transformation of organic mass of coal at 10%.