Introduction. Within the framework of current educational reforms, a trend towards raising requirements for intellectual and psycho-emotional abilities of all educational process participants has become evident. With an increasing number of emotionally intense events, the issue of forming and maintaining the emotional well-being of schoolchildren is becoming more urgent. The key feature of the school environment is emotional well-being, which the authors define as a stable and emotionally positive state of a child in the learning environment; and which is based on satisfying one’s age-related needs, awareness of one’s own emotions and possession of the skills of emotional regulation and reflection.Aim. The article aims to formulate and analyse the problem of emotional well-being, to provide an overview of scientific approaches to its operationalisation, and to determine methodological foundations and directions for assessing the emotional well-being of Russian schoolchildren.Methodology and research methods. Research methods include a review of scientific works by contemporary Russian and foreign scholars; systemic, comparative, and logical analysis of modern approaches to the notion of emotional well-being of schoolchildren. The research methodological foundation is rooted in the provisions of positive psychology, the concepts of subjective well-being (N. Bradburn, E. Dinner) and psychological well-being (C. Ryff), self-determination theory (M. Seligman, R. M. Ryan, E. L. Deci), and ecological systems theory (W. Bronfenbrenner).Results and scientific novelty. The paper determines scientific approaches to analyse emotional well-being of a schoolchild, contributes to the concept of operationalisation, and defines the directions for assessing emotional well-being on the basis of two factors: social environment and personal characteristics of a schoolchild.Practical significance. The research results can be used as a foundation for designing the empirical research into characteristics of the emotional well-being of Russian schoolchildren. The present findings might help to develop a programme for improving schoolchildren emotional well-being considered as a key factor to assess schoolchildren emotional well-being in the learning environment in the context of constant social transformations.