The Majiacun Formation of Upper Cretaceous，with a thickness of 1 960 m，crops out in the Xixia Basin，southwestern Henan ProvinceFrom the base of the formation upwards，the succession is composed of braided river，meandering river and lacustrine sedimentsA lot of trace fossils were found in the fluvial lacustrine sediments，including Skolithos linearis,Cylindricum  ichnosp，Palaeophycus tubuaris,Jshaped burrows,vertical branchedburrows and vertically helical burrows Most of the trace fossils，in terms of their shapes，are supposed to be  domichnia,and can be classified into assemblages of Scoyenia or Arenicolites ichnofacies Based on the lithology of thehost rocks，bioturbation and the total relic fabric，the two ichnofabric typesnamed as soft ground ichnofabric and stiff ground ichnofabric can be distinguishedThe former type of ichnofabric consisted of  Skolithos linearis  and  Palaeophycus tubularis  which occurred in very finegrained sandstones and siltstones，displaying higher density and less diversity of trace fossils,while the latter type of ichnofabric dominated by Cylindricum  ichnosp,Jshaped burrows,vertical branched burrows and vertically helical burrows,occurred in siltstones and thick bed mudstones，exhibiting less density and more diverse individuals Comparedto the reported continental ichnofabrics，the fluvial ichnofabric varied apparently in the Cretaceous，and shallow lacustrine ichnofabric showed that the trace maker’sability to bioturbate the substrates increased obviously with time passing