The features of professional activity of teachers of domestic educational establishments of school type are considered. The basic functions of teacher are described. Going is rotined near forming of discipline of students according to public requirements. Basic work of teacher assignments are certain on realization of educate aims of school. It is marked that professional activity of teacher in the direction of forming of the disciplined conduct consisted of realization of gnostic and organizational functions. It provided for: forming of the system of professional knowledge of teacher; ability to organize educational and outside educational activity of students.