Abstract: So far, both oil and gas found in Qaidam Basin are distributed around the Jurassic, Tertiary and Quaternary hydrocarbonrich sub-sag areas. In recent years, surrounding hydrocarbon-rich depression in petroleum exploration, Kunbei and Yingdong, the two "hundred million tons grade" oilfields, "hundred billion cubic meters" gas in the eastern front part of Altun Mountain and "hundred million tons grade" tight oil in Zhahaquan exploration area have been discovered, and the exploration has made great success. Along with the construction of ten million tons of plateau oil and gas fields in Qaidam Basin and the urgent need of finding new fields and new exploration areas and with the aid of major science and technology projects of Petro China, the authors used the data of boron element and clay minerals and employed Couch formula to carry out paleosalinity recovery, and finally confirmed that the Cenozoic sediment is salty lake deposition in Qaidam Basin. Comparing the Cenozoic salty characteristics of Qaidam basin with those of known hydrocarbon-rich depression in combination with organic geochemical test data of Yiliping depression, the authors hold that Yiliping depression is a potential hydrocarbon generation depression and is probably a new hydrocarbon-rich one. The oil and gas exploration surrounding the depression will be a new successive field and should have important strategic significance in oil and gas exploration in Qaidam Basin.