The modern process of training proceeding in the information and education environment demands a textbook of a new format differing from that one of a traditional paper book. Research has shown that a new textbook is a specially designed subject information and education environment. Filling of this environment (the textbook - navigator, the textbook script, a set of materials for independent work, etc.), structuring information (as the script of an educational process, the designer of a process of training, the integrator of the specified types) is shown in the article. Characteristics of textbooks of a new generation are provided: orientation towards realizing the complete process of training from positing aims to a reflection of results, ensuring the maximum independence of pupils, accounting of specific features of pupils, granting opportunities of creation by pupils of an own educational product. Components of the subject information and education environment are presented: subject and target, substantial and organizational, estimated and reflexive components. The reformative and constructive tasks providing an activity orientation of the electronic textbook are considered.