Abstract: Paleogene braided river delta and meandering river delta are well developed in Gudong area They are composed mainly of coarse clastic rocks such as conglomerate, pebbled sandstone and sandstone, and are the major types of sedimentary facies in the study area. There developed raided river delta plain, braided river delta front and pre ?braided river delta, in which braided river delta front is the major deposits. Channel deposits are well developed with sandbodies in layers as a whole and being composed of several superimposed channel sand lens coarsening downward. Cross stratum, especially side cross stratum, are well developed and the lighologies are mainly of grain supported conglomerate and sandstone. Multidisciplinary analysis of petroleum geology demonstrates that the braided river delta conglomerate and sandstone bodies have good poroperm characteristics, thus are relatively good reservoirs in the study area.