Abstract: Detection and recognition of small objects,such as bottom-mine and buried-mine etc.,becomes imminently and imminently in military application.Following an introduction of state-of-the-arts of small buried-objects detection,the paper intensively analyzes the technical difficulties of small buried-object detection and summarizes the developing trends of buried object detection by using acoustic techniques,which included: lowering the operation frequency,de-veloping detection techniques of SAS(Synthesized Aperture Sonar),exploring time-reversal and MIMO detection methods,recognizing small-object jointly using image and scattering signatures,and so on.These are significant guiding technical research and relevant sonar design on small-object detection.