Deep prospecting is an important orientation for future resources exploration. The existing metallogenic theory and prospecting practice also illustrate a great potential of the deep exploration (with a depth >500m). Key questions for the deep prospecting are as folmows: How to carry out deep prospecting? What type mine to explore? At what depth mines can be found? What technique needs to employ so as to develop the deep prospecting? On the basis of analyses on the metallogenic rules and characteristics of the Lower-and Middle-Yangtze River metallogenic belt, and combined with the principle of metallogenic defaulted prediction, the paper mainly studied the potential of the deep prospecting and major prospecting target layer of the metallogenic belt, and put forward one basic prospecting principle for the deep exploration: metallogenic system analysis, stereoscopic mapping and drilling validation. Taking the Tongling deposit-intensive area as instance, the paper exhibited preliminary results about deep metallogenic forecast in recent years. The main purpose of this paper strikes a wide discussion on the deep prospecting so as to set up a practical exploration procedure and technique methods, and finally guide exploration in deep and peripheral areas around existing mine with resources crisis.