Based on the multilateral agreements modern intergovernmental trade and economic relations are undergoing a transformation now. The liberalization of tariff measures has reached its limit. The use of subsidies a government support mechanism for domestic producers has intensified, but has become the main target of criticism in international trade relations. Companies can increase or artificially maintain their market share by means of subsidies that make them an effective protectionist mechanism. In this context the criterion for classifying support measures as subsidies are crucial for international trade relations. A comparative legal analysis of legal acts and international agreements defining subsidies is given in article: the concepts of subsidies established in US, Russian Federation, Kazakhstan, EU and EEU legal acts have examined element by element.