To investigate the features of bioturbation in shallow-water fan delta front deposits.The core from the 3rd Member of the Paleogene Shahejie Formation from the Well Shenjian-5 was studied,which was deposited in the shallow-water fan delta front in the Damintun Sag,Liaohe Depression.Methods:We have identified the trace fossils, counted the bioturbated layers thickness and bioturbation index along with the vertical core profile.Based on the relevant elemental parameters,we have discussed the relationships between the depositional environment and the bioturbated layer thickness and the bioturbation index.Results:The results show that bioturbation structures were developed in the core of S34Ⅱand S34Ⅰoil layer groups,and characterized by the dominance of the Palaeophycus and Planolites trace fossils. Bioturbation structures were found mainly developed in the inter-distributary bay deposits.The thickness of bioturbated layers was from 5 to 51 cm,and the bioturbation index was from 3 to 5.The thickness of bioturbated layers and bioturbation index varied with no clear evolutionary trend along with the vertical profile.Conclusion: The analysis of elemental parameters showed the paleoclimate,paleoproductivity, paleosalinity,and paleowater depth conditions of S34Ⅱand S34Ⅰoil layer groups were similar,which was the relatively warm and humid paleoclimate,low paleoproductivity,freshwater to brackish water salinity,and shallow water environments.The similar depositional environment was the main reason caused the small differences in the thickness and bioturbation index of bioturbated layers between S34Ⅱand S34Ⅰoil layer groups,as well as for the non-significant evolutionary trend of bioturbated layer thickness and bioturbation index in the vertical profile. However,it is currently difficult to determine the main factors influencing the bioturbated layer thickness and bioturbation index in a single oil layer group.This study not only enriched the evidence for identifying the terrestrial shallow-water fan delta front environment but also deepened understanding of the features of the trace fossils and bioturbation intensity in this environment.