Low-Temperature coal tar pitch is the residuum of coal tar distillation, Its productive rate covers 54% to 56% of coal tar. Low-temperature coal tar pitch is composed by more than three-ring aromatic compounds and oxygen, nitrogen, sulfur-containing heterocyclic compound and a small amount polymer carbonaceous substance. Bitumen component molecular weight between 200 and 2000, up to 3000. Medium temperature pitch is defined according to the softening point. Medium temperature coal tar pitch’s softening point is 65 ~ 90 ℃.