The article deals with the analysis of the phenomena of environment, educational environment and developmental environment; the author considers the significance of developmental teaching in the process of five-year-old children's education, determines the principles of building a developmental environment, emphasizes its necessity in five-year-old children's gaining preschool maturity. An environment is the main means of the development of a child's personality, the source of knowledge and experience. The most important role of the environment is in the development of a preschool child but this aspect of the problem has not been investigated fully enough. The notion of an environment is broad and includes the whole of external conditions, factors and objects where the object is born, lives and develops. The creation of educational and developmental environment in preschool institutions is an important direction in preschool education reforming, namely pre-prep education as a link between preschool and primary education. From the point of view of psychological context developmental environment is a definitely ordered educational environment, in which developmental teaching is carried out. The main features of educational developmental environment for preschool children are the following: partnership between the subjects aimed at child's personality formation, providing psychological defense of a child; knowledge, abilities and skills are considered as a means of a child's further personality development; organization of a child's active living and his creative life oriented at the formation of preschool maturity; continuity which is expressed through the cooperation and succession in creating educational integration "educational institution-school"; exposure which stipulates wide participation of all the members of education in management, democratization of the methods of teaching, education and cooperation; pedagogical support as a special teacher's attitude. Thus, developmental environment in preschool education is a complex of psychological and pedagogical, material and technical, aesthetic conditions which provide the organization of five-year-old children's activity at preschool institution aimed at their gaining preschool maturity. It should address a child's needs, enrich the development of specific types of activity, provide the space for a child's immediate development, to develop creative abilities, to form elder preschoolers' personality traits and life experience before entering a school.