In the presented article an author is analyze social work as type of professional activity and is carried out the sociological analysis of specialists of social work as key subjects in the field of social work. As social work is important direction of activity in any state, it methodological bases, key tasks and main principles though are something alike, however differ depending on legal, organizational, financial possibilities of the state and necessities of clients. Specialists of social work provide realization of social work on national, regional and local levels on enterprises, in establishments, organizations of different pattern of ownership. Professional activity of specialists of social work in Ukraine must correspond the basic requirements and tasks, to certain in Order of Ministry of social policy of Ukraine from 25.05.2012 year «About assertion of new release of qualifying description of profession «Specialist on social work»». In the article is also analyses the short history and features of social work as the type of professional activity in Ukraine, professional requirements to the specialists of social work, their task, role and function are specified. It is set that a necessary condition for a capture this profession is social orientation of personality, presence of the proper social qualities, such as: humanism, goodwill, justice, to responsibility and others. One of entrance terms of efficiency of social work is the presence of skilled shots of the proper level. A considerable value for successful professionalism has an orientation of specialist of social work which plugs the system of values and motivation of him to activity. For a social worker as the professional an important place is occupied by the awareness of itself by the subject of professional activity, that is professional identity.