Through the study of rock types, wall rocks, volcanic debris, hydrochemical cements as well as the texture and structure characteristics of the volcanics, the paper holds that volcanics in the Oulituozi area were formed by su bmarine central volcanic eruption， which are mostly of the composite vol c anic cone type. Moreover, based on the study of the structure of the volcanic co nes, three isochronal amplitude slice models were set up for identifying differe nt kinds of volcanic cones. When these models are applied in combination with se ismic profiles and core analysis, existence and distribution of the volcanic cones can be ascertained.