近年來，隨著WTO (World Trade Organization，世界貿易組織，以下簡稱WTO)市場開放與國際競爭之加劇，全球的反傾銷控訴案件迭起，並促使WTO反傾銷爭端案件有增加之趨勢。「瓜地馬拉課徵墨西哥波特蘭水泥反傾銷稅」 (Guatemala-Anti-Dumping Investigation Regarding Portland Cement From Mexico) 貿易爭端案，係WTO首次依據「反傾銷協定」 (Agreement on Implementation of Article VI of GATT 1994，以下簡稱ADP協定) 所作出之裁決案例。在該案中，一方面，被控訴國瓜地馬拉因未具有足夠證據而對墨西哥水泥展開反傾銷調查程序，違反WTO反傾銷協定之實體義務。然由於墨西哥未能於「成立爭端解決小組之請求」中適當確認特定之反傾銷措施，致上訴機構認為爭端解決小組對本案並無管轄權，並作出墨西哥敗訴之最終裁決。另一方面，雖然上訴機構未對本案進行實質審查，然爭端解決小組之裁決報告首次對展開反傾銷調查之「證據門檻」作出明確要件，對進口國調查主管機關展開反傾銷調查之決定有著重要之影響。本案所涉及之貿易法程序及實體規範，對我國相關決策單位及廠商，實具有相當的啟示意義。

Portland Cement case is the fist antidumping dispute considered by either a WTO dispute settlement panel or the WTO Appellate Body. On the one hand, Guatemala has violated its obligations under the WTO Anti-Dumping Agreement by initiating the investigation without suffieient svidence, while, on the other hand, Mexico has failed to comply with the provisions of the DSU since it did not properly identify the measure challenged. The outcome of this difficult case should provide considerable insight into the way future Taiwan may apply.