The subject of the study is public relations in the field of administrative and legal regulation of the customs and tariff mechanism of foreign economic activity. Methodology. The instrumental and methodological apparatus of the research is formed by the applied methods of economic analysis of the activities of organizations, statistical methods, selective observation, the method of economic modelling, grouping, generalization, expert assessments, methods of economic theory, marketing, etc. The aim of the article is to analyse the administrative and legal aspects of the mechanism of customs and tariff regulation in modern conditions in Ukraine and the world. The research results in a comprehensive consideration of the system of administrative and legal regulation of the customs tariff mechanism in Ukraine and the world, within which: the impact of the customs tariff mechanism on foreign economic activity is assessed; the modern foundations and principles of tariff benefits and protectionism policy are highlighted; the analysis of the administrative legislation of the studied area is carried out; weaknesses and problems of administrative and legal support of the customs tariff mechanism are identified, and ways of their solution are proposed. Conclusion. Customs and tariff regulation acts, on the one hand, as an effective regulator that promotes greater openness of the market, on the other - as the most common foreign trade instrument of protectionism. Therefore, improving the problems of customs and tariff regulation in modern conditions is simply necessary to overcome the crisis phenomena in the domestic economy and ensure the economic security of the state. After all, it requires the determination of the maximum level of tariff rates of import duties, which, under the normal functioning of the economy, will not increase and may be reduced in the future. Such plans may shock many sectors of the domestic economy. These primarily include agriculture, the food industry, the pharmaceutical industry, and the leather and shoe industry. Customs and tariff regulation is designed to promote the goals and objectives of foreign economic activity, as well as ensuring the security of the country and protecting national interests. The methods of customs and tariff regulation are more consistent with the nature of market relations and therefore play a major role in regulating foreign economic activity. In modern conditions, customs and tariff regulation can and should become an effective tool for mitigating and gradually overcoming crisis phenomena in the economy.