Abstract: In this paper, the liquefaction reactivity of the lithotype and maceral of low rank coal was studied in autoclave when solvent and catalyst were used in the hydro-liquefaction test. The experiment results indicate that the conversion and the oil yield are in the sequence of vitrain, clarain, durain and fusain for macro-lithotype of coal. At the same time, for micro-maceral, not only vitrinite, exinite have activity, but also semi-vitrinite has certain activity, and the content of the active component (vitrinite, semi-vitrinite, exinite) increases linearly with the conversion and the oil yield. Semi-fusinite has activity in liquefaction when the reflectance is less than 1.5%, but its activity is less than that of semi-vitrinite in the same coal, and inertinite does not have any activity when the reflectivity is more than 1.5%.