Abstract: In order to discuss the origin and migration of crude oil in the Yanchang Formation, an attempt of palynological study has been made and some pollen and spores have been found from the crude oil of this formation. The procedure of filter method in separation and maceration is introduced. Miospores of 20 species belonging to 16 genera, one kind of fungal spores as well as fragmental remains of algae origin are described and illustrated; three new combination are suggested. Judging from the facts that nearly all the fossil pollen and spores from the oil samples are already known from the assemblages of the wall rocks, though far less in forms and number, and that the geological age indicated by the present assemblage is not older than the Yahchang Formations a conclusion is arrived at that the crude oil was transformed from kerogen of the Yanchang Formation and the reservoir oil is indigenous or secondary through short distance migration.