在國際貿易盛行之今日，同一發明申請多國專利乃普遍現象，發生訴訟時，若前訴於外國法院已就特定爭點進行審理，於本國法院之後訴應無重覆審理之必要，此對於訴訟經濟、效率，甚至公平性均有實益。然此情況無法以既判力處理，因為即便發明標的相同，前後訴當事人及被控物很可能不同，不符既判力原則致無法適用，而英美法之爭點效則能提供救濟，故爭點效對專利訴訟十分重要且為我國所需。 與美國法制比較後本文認為，若要建構處理域外判決及申請歷史對內國專利案件之爭點效，應對三種法規進行修正，第一，排除效法規、專利法規，及證據法規。有關排除效法規之修正，乃著眼於爭點效理論自駱永家教授引進至今，理論尚持續討論中，而未有明確法規建立，實務上卻有領先法規之判決，出現較類似英美法系中之法官造法現象，故應儘速修法因應。有關專利法規之修正，乃著眼於我國在可專利性、申請專利範圍解釋等，與他國之規範有所不同，應致力與國際接軌並調和之。有關證據法規之修正，乃著眼證據分類，舉證責任分配，證據力，及證明度（升高）等機制尚待明確建立，亦應努力改進。

In light of the situation where an invention asserted in multiple suits against infringers in different countries happened more frequently, the doctrine of issue preclusion had become increasingly important to patent litigants. However, claim preclusion cannot provide resolution to it because the parties and accused products may not be the same between the first and second judicial proceedings, despite of the same invention at issue. Instead, we need to establish the issue preclusion mechanism to our patent system to acquire efficiency, while avoiding inconsistent judgments. After comparing with the U.S. system, this article suggests that, in order to establish issue preclusion based on the foreign patent judgment and prosecution history, our patent system is currently in want of reform. In particular, there are three kinds of regulations to which we must conduct reform, i.e., preclusion regulations, patent regulations, and evidence regulations. Although Professor Louch had introduced the concept of issue preclusion into our country decades ago, the statutes as a whole have not been properly constructed to serve as a functioning platform in this regard. Ironically, associated statutes are preceded by courts’ issue preclusion decisions rendered to certain cases, a judge-made law phenomenon which does not traditionally appear in a civil law country due to lack of the stare decisis mechanism. We hereby must manage toamend the current statutes to lay out a proper foundation for providing issue preclusion effect needed. To be effectively applying issue preclusion, it is necessary to ensure the satisfaction of the “identical issue” requirement which turns out to be the most complicated one among the four factors test initiated by In re Freeman due to the variances of regulations among countries. Therefore, we need to harmonize our patent regulations with the rest of the world. While file history itself is intrinsic evidence, however it becomes extrinsic evidence when containing a statement made to foreign counsel or patent office examiner. We need to amend the regulations of evidence classification, and even provide a heighten-of-standard-of-proof mechanism to deal with extrinsic evidence such as file history.