Abstract: As the oil and gas exploration goes further, more and more oil and gas resources are discovered. How much oil and gas remain to be discovered in mature oilfields is an important question for petroleum geologists. The paper presents the exploration benefit approach to assess remaining oil potential in the Jinhu Sag, North Jiangsu Basin, and briefly discusses the principles and steps of the exploration benefit method in oil and gas resources assessment. Research shows that the oil and gas reserve undiscovered in the Jinhu sag is about 3320~36701 ×04t. Practice proves that the exploration benefit method slides over the problem of oil and gas genetic mechanism in reason and reduces the subjective impact on oil and gas resources evaluation effectively, which makes the results of oil and gas resources evaluation more objective. So the method will have broad prospect for application

Key words: exploration benefit method, Jinhu sag, oil and gas resources, application