Thirty years have elapsed since tie nationwide petroleum reconnaissance announced its beginning in North China Plain in 1955 During tiis period, integrated geophysical survey has been carried out in dozens of continental or off-siore depositional basins with the discovery of hundreds of structural traps of various types, of which some one hundred have proved by later investigation and exploration to be oil fields of commercial value; nevertheless, the geophysical work in this thirty years, named "the first round petroleum geophysical reconnaissance", has been predominantly confined to various anticlinal traps within Mesozoic and Cenozoic detrital sequence of East China. Starting in about 1982, the second round petroleum geophysical reconnaissance extends the investigation and research work to new areas, new depths, new realm and new types with the aim of looking into complex structures and stratigraphic traps. To fulfil the task assigned to tiis round, full use should be made of the experience gained in the first round, such as spreading the survey to the whole region, integrated exploration with seismic prospecting as the major method, and integrated evalution. Tie present paper also maintains that tie successful realization of tie new objectives requires new viewpoints, new equipments, new techniques and newly-trained personnel.