Abstract:Four-dimensional seismic reservoir monitoring technique is a new technique which has been developed in recent two years. The authors describe its conception and data processing,its applications in improving hydrocarbon recovery and optimizing hydrocarbon development,its foreign research status quo and its foreign application effect. They also expound necessity,possibility and problems of conducting four-dimensional seismic monitoring in China. It is pointed out that high-resolution seismic image is both an important means of researching into the four-dimensional seismology and the key of achieving successful four-dimensional seismic monitoring technique.