Abstract: Through the reflectance and pyrolysis analysis of Jurassic coal, north east of China, it is believed that there are various types of vitrinization and fusinizotion sclerotinites. Those different kinds of sclerotinites have different activities in our low temperature pyrolysis experiments. According to those different pyrolysis activities,sclerotinites can be divided into three parts: Active sclerotinite; Subactive sclerotinite; Inactive sclerotinite. The former is often shown by vitrilization sclerotinite which could be further recognized as A or B subtypes. The second always linked with semifusinized sclerotinite. The last one include superfusinization and fusinization sclerotinite.