This article reviews a recent Formosan(=Taiwanese) court judgment on paternity suit after the death of the father. After the law reform in 2007, Formosan Civil Law now allows the paternity claim after the death of the father. Before 2007, paternity claim after the death of the father can only be brought on the ground that the father had acknowledged the parentage by way of giving maintenance to the child. In a recent case, the child brought paternity suit before the law reform, requesting the court to confirm the paternity. The claim was rejected by the court on the ground that there was no sufficient evidence to prove that the father has, before his death, provided maintenance to the child. After the law reform in 2007, the child sued again and referred to the new law. The District Court and High Court have affirmed the paternity according to the new law, but the Formosan Supreme Court has overruled on the ground of the so-called "issue preclusion" effect of the previous judgment. This article analyzes the reasoning of the Supreme Court, and concludes that it is wrong.