Abstract: Analysing the success of exploratory well, situation of oil and gas reservior discovering, oil and gas reserves conrtolled by single well in Xihu Troigh, the East China Sea, further exploring domains are suggested:south of the Trough and Pingzhong, Pingbei Zong in Baoshu Slope are main areas for discovering large-medium size oil and gas fields and greatly increasing reserves; Shallow secondary oil and gas pools should be think highly in the mid-and northern Zhedong Center Anticline Zone; Paleocenic petroleum trap may be occurred in northern and.southen Baoshu Slope, which not be penetrated up to now in Xihu Trough.