The Paleogene Shahejie Formation is the main petroliferous stratum in the Bonan Sag of Jiyang Depression in Bohai Gulf Basin.The features of the distribution of sedimentary facies of every member of the Shahejie Formation are various and the evolution of sedimentary facies is clear. During the early period of the fourth subage of the Shahejie Age, it is characterized by well-developed fan delta facies, which located in the south part of the Bonan Sag. Inshore-submerged fan was developed in the north margin, braided delta facies was lain in the east and west, and deposits of salty lacustrine were located in the center. During the late period of the fourth subage, it is characterized by well-developed salty lacustrine facies, which located in the deep-water area of the Bonan Sag. Semi deep-lake subfacies, shallow lake subfacies and lakeshore subfacies were developed respectively around the salty lacustrine facies. Moreover, there were some small-scale braided deltas locally. The third subage of the Shahejie Age was the period of full bloom of braided deltas. During this period, braided deltas were located in the southeast part of Bonan Sag. The main source area was Gudao Salient. Sandstone bodies of braided delta front are the most principal reservoir in which almost oil of Bonan Sag was preserved. The lacustrine facies was also developed throughout the third subage, especially the deep-lake subfacies and semi deep-lake subfacies were well developed. Through the uplift, erosion and sedimentation during the post third subage, the lacustrine basin of the second subage shallowed and mainly composed of shallow lake subfacies. Braided deltas with an extensive area were developed in the southeastern and northwestern of the study area. During the first subage, source area retreated with a large scale transgression of the lake. There only was lacustrine facies developed in the study area, in which the deep lake subfacies and semi deep lake subfacies were over prevailed.