Abstract:Fifty-one species of fossil spores and pollen referred to 35 genera extracted from the crude oil samples taken from the Dushanzi Oilfield of the Junggar Basin in the Xinjiang Province are investigated in this paper. Based on the investigations of the spores and pollen in crude oils, petroleum source of the region are traced and problems on petroleum migration are discussed. The spores and pollen found in the crude oil samples collected from the Tertiary reservoirs of the Dushanzi Oilfield are mainly of Leiotriletes adriensis; Cyathidites minor, Dictyophyllidites harrisii, Murospora jurassica, Marattisporites scabratus, Aratrisporites xiangxiensis, Schizosporis microreticulatus, Cycadopites nitidus, C. typicus, C. minimus, Callialasporites dampieri, C. radius. Paleoconiferous asaccatus, Pseudowalchia ovalis, P. landesii, Podocarpidites multicinus, P. muhesimus, Ovalipollis enigmatica, O. minor,Caytonipollenites pallidus, Pteruchipollenites thomasii, Alisporites grandis, A. bilateralis, Piceites pseudorotundiformis, Abietineaepollenites dunrobinensis, A. minimus, Pinuspollenites labdacus maximus, P. labdacus minor, Piceaepollenites alatus, Cedripites canadensis, TsugaepotIenites viridifluminipites, Taxodia ceaepollenites hiatus, Ephedripites eocenipites, E. fusiformis, E. tertiarius, E. scobridus, Eucommiidites troedssonii, Salixipollenites discoloripites, Quercoidites henrici, Q. microhenrici, Q. asper, Rhoipites pseudocingulum, Caryapollenites simplex, JuglanspoUenites verus, Liquidambarpollenites stigmosus, Chenopodipollis psilatoides, C. minor, Artemisiaepollenites sellularis, Tubulifloridites macroechinatus, etc. Some of the microfossils belong to Jurassic, and some belong to Tertiary in age. Judging from the fossil spores and pollen in crude oils, two series of petroleum source rocks might exist in the southwestern petroleum province of the Junggar Basin. They belong to the Lower to Middle Jurassic Badaowan to Toudenhe Formations and the Oligocene Anjihaihe Formation respectively.