農業在WTO杜哈回合談判中是一項非常重要的關鍵議題，特別是在關稅調?方面，以達市場實質開放的目的。由於各項農作物在整體農業資源配置中息息相關，因此本文擬以臺灣農業部門模型為研究方法，針對各種可能的關稅調?方案，進?社會福?變動、生產者剩餘變動、農業產值變動、農業?動變動，以及種植面積變動之模擬，希望在此衝擊效果評估下，以作為談判決策之?考。依模擬結果顯示：關稅調?程?愈大，所增進的社會福?也愈多，其對於需求彈性較大的產品，所增進的消費者剩餘也較多，但對於供給彈性較大的產品，其減少的生產者剩餘也較多。基本上，關稅調?幅?愈大，農業產值減少程?也愈大，但考慮到各個產品的產值高低，在關稅平均?幅相等的條件下，可透過?同產品關稅?幅?等的分配，達到?低整體產值減少的目的。由於農業多為??密集產業，故關稅?幅愈大，對於?動?投入減少的影響也愈顯著，預期至少將改變農業?動的投入結構，以及在兼業農戶之中以農業或非農業為主的比?。此外，因關稅調?較大的產品多為土地?用型，故對其衝擊較大，且土地?用型的產品並?一定與其產值高?相關，談判策?尤應考?產值或種植面積何者優先，前者與農業生產所得息息相關，後者則直接影響政府休耕支出及休耕土地?用的問題。

The purpose of this study is to evaluate the economics impacts of the alternative tariff reductions on social welfare, producers' surplus, agricultural production value, labor, and planting acreage by using Taiwan Agricultural Sector Model. Such empirical estimation results may have important implication for policy decision. Our findings show that the social welfare increases as the tariff reduction increases while consumers and producers surplus depend on demand and supply elasticity. Higher demand and supply elasticities results a significant change both in consumers and producers surplus. We also found that the tariff reduction level significantly affects agricultural production value. However, such impact for each individual product is different regard of same tariff reduction level. The impacts of tariff reduction on land and labor usage is also significant which implies possible policies adjustment with respect to factor markets are needed.