By means of observation of cores and identification of specimens, a lot of trace fossils including Mermoides chezhenensis, Helminthopsis sp., Gordia sp., Helminthoidichnites sp., Planolites beverlegensis, Neonereites uniserialis and Planolites sp., are discovered in deep water sediments in the Shahejie Formation of Paleogene in Chezhen Sag, Jiyang Depression of Bohai Bay Basin. They are grazing trails and feeding trails produced by invertebrates such as annelids, arthropods, gastropods, and so forth. Of these trace fossils, Neonereites uniserialis, with 7 cm in length and 2 mm in width, is a chain of knobs forming unbranched meandering shape and is preserved in convex epirelief in gray, dark gray shales. Mermoides chezhenensis, which is simple, irregularly curving in shape, ranges from 1 to 3 cm in length and 1 to 2 mm in width. The trace is preserved parallelly or slightly obliquely in gray, dark gray thin-bedded mudstones. According to their palaeoecological and sedimentological features, these ichnofossils can be divided into two ichnoassemblages, namely, Mermoides chezhenensis Ichnoassemblage and Neonereites uniserialis Ichnoassemblage. Mermoides chezhenensis Ichnoassemblage, which is characterized by the fully abundant Mermoides chezhenensis ichnospecies and commonly associated with Helminthopsis sp., Gordia sp., Helminthoidichnites sp., and Planolites beverlegensis, occurs in gray, dark gray thin- bedded mudstones. The Ichnoassemblage often has high ichnodiversity and abundance and represents highly oxygenated semi-deep lacustrine sediments. Neonereites uniserialis Ichnoassemblage, consisting of ichnogenera Neonereites uniserialis and Planolites sp., develops in gray, dark gray shales and indicates semi-deep to deep dysoxic lacustrine environment. The Mermoides chezhenensis Ichnoassemblage has similar characters as Mermia ichnofacies in composition, ichnodiversity and abundance of ichnoassemblage. The Neonereites uniserialis Ichnoassemblage has lower  ichnodiversity and abundance compared with the Mermia ichnofacies and the chemical characters of water represented by the trace assemblages are also different. The present continental trace fossil model is not complete, and there are still many ichnofacies that haven’t been recognized and established.