The implementation system of the recommendations and rulings of the Dispute Settlement Body is an important component of the WTO dispute settlement procedure. Where there is any disagreement between disputing parties as to the existence or consistency with a covered agreement of measures taken to comply with the recommendations and rulings, a winning party may refer the matter to a compliance panel and the Appellate Body. If a losing party is found to have failed to comply with the recommendations and rulings, DSB may authorize the winning party to retaliate. This article analyzes the implementation system of the WTO dispute settlement procedure in comparison with other systems of ‘second-order’ compliance in international law. Also, attention will be directed to the relationship between the WTO retaliation and countermeasures in general international law. Countermeasures under the Agreement on Subsidies and Countervailing Measures, in particular, have a legal nature akin to that of countermeasures under the law of State responsibility.