When Lithuania became a member of European Union, the educational institutions are eager to join common educational space and modern educational tendencies of the world. One of the most important problems is the modeling of school network basing it on the experience of European Union. The following authors have discussed the issue of educational change - A. Fullan (1993), D., Hopkins, M., Ainscov M., West (1994), Ch., Lusthaus (1997) etc. R., F., Crisholm (1996) indicates that a network is the perspective for the XXI age. It causes no doubt for the number of schools joining into networks is increasing (e.g. Network of Open Colleges (1897), Eurydice - European Education Information Network (1990), European Distance Education Network (1991), etc.).The aim of the article is to form the stages of a school network development. The objectives of the research are as follows: To discuss the concept of a school network. To carry out a qualitative research of the school managers. To reveal the stages of a school network development.The following research methods were applied in the research: The analysis of the scientific references. Basing on the research of various scientists and the conceptual attitudes the concept of a school network and its development stages are grounded. Document analysis. A number of legal acts related to the educational policy, its change and improvement are being analyzed. Content analysis. Finds out the attitude of the school managers towards the activity guidelines of the school network being developed. Hypothesis of the research argues that a school network that is developed under new conditions creates prerequisites and opportunities for parity cooperation of various types of schools and becomes similar to the networks in European Union. The following conclusions are being drawn after generalizing the analysis of the ideas of the scientific references, conceptual documents on education and research:1. A school network is cooperation among various type educational institutions based on non-hierarchical relations and that are united by common goals and mutual benefit. 2. The managers of educational institutions understand the importance for cooperation as a prerequisite for parity relations by sharing information and innovations not only among network members but also in the achievement of the network goal and vision, they grasp the purpose of a network - to help in the realization of needs and interests.3. The development of a school network consists of seven stages: Start-up of the initiative group and its development; Situation analysis of every organization school- a network member; Defining the conceptual purpose, mission and vision of a network; Start-up of the strategic group of a network; Design of a network development strategy; Discussion of a network development strategy and its correction; Network realization.