The Huanghua downwarping basin is one of the important oil-gas areas inChina. With the deepening of exploration work, the oil-controlling role ofintermediate-basic volcanic rocks has aroused great interest among petroleumgeologists.The results obtained recently in the large-scale high-precision aero-magnetic survey over the central part of the Huanghua downwarping areaalso clearly show shapes and different distribution characteristics of concealedvolcanic rocks related intimately to oil-gas. North of the Kongjiazhuang-Xuji-apu line, anomalies of volcanic rocks are mainly two-dimensional ones, indica-ting the zoned distrlbution of volcanic rocks along fractures. To the south,however, there are mainly isometric anomalies produced primarily by volcaniccones. These facts suggest that there exist obvious differences in geological-structural characteristics of this area. These outcomes are of great significancefor evaluation of oil-gas resources in this area.