Tariff concession will affect the domestic price , the advantage of producer , the welfare of consumer and the revenue of government directly and indirectly . the direct effect is that tariff reducton depress the protect level of the agricultural and it will impact on the domestic agricultural market 对农产品关税进行减让，直接和间接地影响到了进口国的市场价格、生产者利益以及消费者的福利和政府的关税收入，关税减让使进口国对国内农产品的保护水平降低，从而对进口国的农产品市场产生一定的冲击。
Firstly , we sum up many natinal and domestic research from five aspects . they include tariff theory and policy , effect of the tariff adjusts , the policy of the agricultural tariff , agricultural tariff concession mode and some important questions in the new round wto negotiation . based on the summary , we can find the problems and try to solve them 首先从关税理论和政策分析、关税调整的效应分析、农产品关税研究、农产品关税减让模式研究以及新一轮wto农业谈判中的重点问题等五个方面对国内外的已有研究进行综述，针对已有研究的不足提出本文研究的思路利方案。
