The monograph describes the pedagogical concept of phenological work at the level of primary general education. Based on a retrospective analysis of the use of observations of seasonal changes in nature, identifying the structure of the educational activity of a primary school student, a model for the formation of universal educational actions through phenological work is proposed. A pedagogical experiment is presented and its results are discussed. The monograph is intended for students, undergraduates, graduate students of pedagogical faculties, primary school teachers, primary education methodologists, teachers of additional education for children, and anyone interested in the possibilities of organizing observations of seasonal changes in the nature of their area.