The relevance of the present issue is caused by the need for carrying out lifelong learning of teachers as an essential condition of their professional development. The aim of the article is to prove the necessity of integrating formal and informal professional and optional development of educators. The main methods of the research are analysis and synthesis of the data obtained. The authors hold an analysis of the lifelong learning development in the EU countries and in Russia, which can be formal and informal. The latest represents an entirely new phenomenon in the social and educational practice. Its content bases on their own principles, carries out specific functions and solves existing problems in an innovative way. The article also views the strategies and models of lifelong professional education of teachers being under a significant pressure of informational and communicational technologies and relying on informal mechanisms of giving knowledge and forming competences. In the research part of the article the objective and subjective difficulties of teachers and their professional needs are revealed. Lifelong learning is bound to overcome these difficulties and satisfy the necessity of forming and developing new professional competences. The analysis of the documents of educational institutions shows the dominance of informal education. It proves the need for defining the status of informal education as a constituent part of professional development of an educator.

lifelong learning of teachers, informal education, personality-oriented trajectory of continuous education, models and strategies of lifelong learning, professional development of an educator.