Objectives: Western Liaoning Province in our country has been an important producer of Mesozoic fossils, a large number of rare animal and plant fossils was found and had a significant impact in recent years, but the layers of fossils remains unclear, this time we are going to solve this problem.  Methods: In the past three years, the author carry out an investigation in detail for a sedimentary rock between two other volcanic rocks in Jianchang、Lingyuan、 Chaoyang、Jianping of western Liaoning. First of all, according to the exposed of Tiaojishan formation，we set the main section in Daxishan Linglongta Jianchang, which located in Jinlingsi—Yangshan Basin, Moreover we measured assisted sections in Dapingfang—Meileyingzi basin and Lingyuan—Sanshijiazi basin;at the same time we excavate fossils layer by layer, in order to determine the stratigraphic horizons which has fossils;after that we researched the fossils we collecting and collected the informations of fossils in western Liaoning;at last we put fossils on the correct fossil bed and comparing fossil beds in different basin. The main methods of this investigation is sectional measurement and fossil collection systematic.  Result: Through out the sectional measurement and fossil collection, we determining a part of fossil beds of the Tiaojishan Formation Middle Jurassic, belonging middle of theYanliao Biota. In order to compare with fossil beds in other basins, we named two fossil beds——Daxishan fossil bed and Guancaishan fossil bed, corresponded fossil with stratigraphic horizons，and completed comparison of fossil beds in different basin；at the same time we excavated anumber of precious fossils.  Conclusions: By the investigation this time, we determining a series of middle Jurassic fossil beds in western Liaoning and collecting many fossils enrich the Yanliao Biota and provid informations for studing and researching for future.