With the development of the international community, public morals have attracted increasing attention from states. Nevertheless, the “public morals” exception clause in Article XX(a) of the General Agreement on Tariffs and Trade (GATT) is hardly invoked by state parties as a distinct basis for trade-restrictive measures. The EC-Seal Product dispute is the first case in which the Dispute Settlement Body (DSB) of the World Trade Organization (WTO) considered this issue, after which it addressed the issue in the Columbia-Textiles and the Brazil-Taxation disputes. This article aims to analyze the kinds of public morals that can be justified while implementing trade-restrictive measures. It proposes that the human rights standard is a significant moral concern and that human rights law and trade law may be integrated. The article also addresses the question on the procedures that should be followed in applying Article XX(a) to avoid abuse. It concludes that Article XX(a) attaches intrinsic importance to striking a balance between trade liberalization and state sovereignty, for which it must be reserved in the GATT.