Abstract: An integrated research has been carried out on the tectonic effects on the hydrocarbon reservoirs of the Qinglong Formation in the South Yellow Sea Basin, based on the drilling, well logging and seismic data from the study area and adjacent areas. The relict Qinglong Formation, which consists of carbonate platforms and shelf deposits, is distributed in this region in NE - NNE direction. The Indochina and Yanshan movements made the Qinglong Formation exposed to air for a long term of strong weathering and denudation, and thus resulted in the formation of karst reservoirs that are favorable for hydrocarbon accumulation. The fractures developed in the Qinglong Formation mainly in NE direction further improved the reservoir properties. The reservoirs distributed around the wells of WX5-ST1,CZ24-1-1 and CZ35-2-1 in a NE trend are selected as the most prosperous ones for consideration.