serif’">According to cure observation and sedimentation analysis, Es3 reservoir of Dongxin area is enriched with trace fossils, which contains dwelling burrow, escape structure, bioturbation structure, biological entity fossil and impression. The ichnocoenosis can be recognized as Domiehnia, Fodiniehnia and Paseiehnia. Based on the distribution characteristics, ichnoenenuses can be subdivided into Coehlichnus anguineus, Planolites montanus and Skolithos-Planolites. The results show that hydrodynamic conditions were enhanced gradually and the water’s depth was getting shallow upward in the depositional period of Es3 member of Dongxin area.