For the four decades after the Second World War, the U.S. took the lead in promoting liberalization of world trade and establishing the rules of game for that trade in the consecutive round of multilateral trade negotiation. But, the large trade deficits and the increased competition in domestic and overseas markets that the U.S. has faced in recent years have called upon a result-oriented trade policy to set the quantitative performance targets. This kind of quantitative target(unofficially 20% target share in Japanese market) was set in U.S.-Japan semiconductor agreement and similar market share target was requested in U.S.-Korea auto negotiation in 1995. In fact, U.S. has frequently counted on an aggressive trade policy to manage its exports in a specific industry, entire volume of trade, or trade balance. This is called the common type of managed trade. The purpose of this paper is to study managed trade which has drawn increased attention to international economists nowadays. This paper studies managed trade as follows: definition, historical background and ideas behind managed trade, actual types and nature of managed trade, and policy instruments of managed trade. Then this paper tries to assess managed trade and gives some thoughts on the prospect for managed trade.