The purpose of the article is to reveal theoretical foundations and conceptual aspects for determining characteristics of environmental and economic security of agro-industrial complex in conditions of sustainable development. Research methods. In the research process general theoretical methods of scientific cognition were used, in particular abstract and logical method (for generalizing theoretical approaches to defining a concept of ecological and economic security) methods of comparison, analysis and synthesis (for determining content of definitions of “economic” and “environmental” security, taking into account particularities of agro-industrial development in context of sustainability). Research results. Methodological compatibility of concepts of “economic” and “environmental” security was established, and an expediency of their essential designing in a field of the agro-industrial complex with the definition of conditions of sustainable development was characterised. Components that shape ecological and economic security of the agro-industrial complex were characterised, and the corresponding consequences for the development of society, economy, and agrarian sector were distinguished. Elements of scientific novelty. Methodological provisions for a conceptual vision of the theoretical characterization of principles of ecological and economic security in terms of sustainable development on an example of the agro-industrial complex were proposed; as well the components of its formation were systematized and compared. Practical significance. The proposed theoretical and methodological provisions should be used to deepen a conceptual definition of principles of sustainable development of economic systems. Figs.: 1. Refs.: 22