1. ��esearch Center of Paleontology �� Stratigraphy��Jilin University��Changchun 130026��China; 2. Bureau of Fossil Protection and Administration of Liaoning��Shenyang 110032��China

Combining with the new data obtained from the fossils for recent years��the author summarizes the distribution and composition of the Jehol Biota from western Liaoning��makes clear on the evolutionary sequences of the biota in several main basins��and analyzes the evolution and geological background of the fossils vertebrates in several main basins in this region�� From the vertebrate evolution��the author has recognized the radiation��convergence and complex evolution in type�� During the Yixian Formation stage��the specific formation events were in existence due to the geographic isolation��and at the Jiufotang Formation stage��the radiation of the pterosaurs and birds is possibly related to the ecological isolation��which was mainly due to the differentiation in feeding�� The evolution of the Jehol Biota is probably as a results of a cooperative action including indigenous species outer immigrating�� the alien species' invasion��the extinction of some species after geographic isolation��and some population in radiation��and complex evolution��which were all co-evolved in a similar geological background�� The volcanic rocks of the uppermost Yixian Formation were passing the stratigraphic boundary with entering the beginning of the Jiufotang Formation stage��