The authors put forward the concept of orefield geology, which covers studies of formation, structure and metallogeny of oilfields.The authors also proposed an idea of prospecting deposits hazed on this concept, i. e., the interface of tectono - lithofacies is a geological basis for prospecting; the tectono - geochemistry interface contains information of prospecting and prediction; and the interface of tectono - physicochemistry reflects the essential of metallogenesis. The authors propose that the integrated exploration area is an exploration domain which consists of one or several orefields.