Abstract: In this paper, development and progress of sonar from its birth to nowadays is outlined. Type, regime, user nations and mounted platform of foreign mainstream sonars in commission are summarized. Study status of foreign sonar technology is analyzed from four aspects, which are multi-function integration, array formation, multi-static cooperation, and open system architecture. Together with operation task requirement and basic support technology, development trend of sonar technology is envisioned from three dimensions, that are fully adaptive intelligent cognitive technology, MIMO technology, and wide domain multi-sensor joint awareness technology.