Abstract: Due to the complexity of geological conditions, there are a lot of geohazards in deepwater areas, which may turn to catastrophes without extensive and prudent consideration. Therefore, in the process of deepwater petroleum exploration and development, site investigation and geohazards assessment are indispensible. Comparing to shallow water area, the cost for conducting site investigation in deepwater is tremendous. In recent years, we have been using 3D exploration seismic data to indentify geohazards at well sites. After high-resolution reprocess, in some cases it is possible to use exploration seismic data to detect and assess geohazards. This paper introduces a case from the Qingdongnan block.