儘管雙邊優惠貿易協定談判已為國際經濟活動之主流，然相關成效卻往往受到其原產地規則寬嚴之制約。過去相關研究有從法律面向討論優惠貿易協定相關問題，或純從經濟角度看優惠性原產地規則對於貿易或投資可能影響，而本文乃係同時結合法律與經濟之探索，特別是根據GATT第24條第5、8項規定來釐清關於優惠性原產地規則之適法條件，並透過經濟之量化估算來作為上述適法條件落實之基礎。最後研究發現，若所訂定之優惠性原產地規則過於嚴苛，則可能將對於非會員之貨品進口較先前更具限制性，且同時對絕大多數在會員國家加工出口之貨品構成歧視，致不符合GATT第24條第5、8項之規定。 This paper explores the legality of preferential rules of origin based on regulations relating to Article 24 of the GATT 1994 and from the perspective of economic effect. The preferential rules of origin- originally intended to be a neutral instrument to protect against trade deflection- were abused by preference-granting countries seeking policy instruments with which to protect their own political and economic interests. With the stagnation of the WTO Doha Round Negotiations, bilateral negotiations and the preferential trade arrangements have become the leading international economic activities. The preferences created through the above preferential arrangements, however, have been eroded substantially by the implementation of the rules of origin. It is therefore increasingly important to investigate whether the rules of origin contained in such preferential arrangements are consistent with the related regulations of the Article 24 of the GATT 1994. We find that it is possible that these are inconsistent with Article 24 (5) and 24 (8), if the rules of origin are too restrictive. Accordingly, we suggest that it would be better for Taiwan in future RTA/FTA negotiations to adopt looser rules of origin on account of networked global supply chains.