Abstract: Few fossils have been found in Late Jurassic Tuchengzi Formation from Qianjiadian District, Yanqing County, Beijing. Nevertheless, the new dinosaur footprints are important evidence of dinosaurs that once lived in Beijing. The study of its sedimentary environment is very important for reconstructing the living environment of dinosaur fauna. There are theropod, sauropod and possible ornithopod tracks in the study area. Based on stratigraphic, petrological, paleontological and sedimentary research methods, the authors used the integrated characteristics of field section, dinosaur tracks distribution, sedimentary structrue and grain size distribution to study the sedimentary environment of the third member of Tuchengzi Formation in Qianjiadian area. There was a volcaniclastic shallow lake here and the dinosaur tracks were formed in a lakeshore environment.