By the application of wave process method, the process of sedimentary—erosion of the Paleogene and Neogene have been analyzed. On the 18 typical wells in 9 different depressions of the Bohai sea area, writers decomposed out 4 low frequency wave cycles and 3 high frequency wave periods as follows: 760Ma, 220Ma, 70Ma, 30Ma and 18Ma, 8Ma, 2Ma. Based on the analysis of the wave characteristics cycled 18Ma and 8Ma which reflects the “Formation” and “Member” level, writers predicted the process of sedimentary—erosion of the time of Kongdian Formation—Shahejie Formation, calculated the erosion quantity of the main unconformities in the Paleogene—Neogene strata and identified the strata erosion quantity at the end of the Kongdian Fm., Dongying Fm. and Guantao Fm., i.e., 0~516m, 0~213m and 0~682m respectively; which were closely related to the oil and gas accumulation. By comparative studying the wave characteristics，the tectonic transition belt have been identified in the study area. The tectonic transition belt during the Kongdian stage was located in the center of Bohai sea area; those duringthe Shahejie and Dongying stage were located in the BZ13 1 2 and LD10 1 1well areas respectively. The tectonic transition belts during the Guantao stage and Minghuazhen stage were located in the LD10 1 1 well area and BZ3 1 3D Well area respectively. And the horizontal distribution of erosion quantities of the unconformities at the ends of the Kongdian, Dongying and Guantao stage, which were closely related to the hydrocarbon migration and accumulation, also have been quantitatively recovered; the distribution regularities of subsidence—sediment areas and uplift—denudation areas in the key stages are reproduced. The understanding mentioned above have important significances to the research on the Paleogene—Neogene oil and gas distribution regularity and to exploration oil and gas in the Shahejie Formation and underlying formations.