The Authors describes the Social Welfare as the main goal of social work. The Article puts focus on definition of social welfare as an integrative factor characterizing the interaction of social subject, environment and regulators dialed with them, which provides balance and consensus of personal and society interests, responds to the subject development needs, and helps him to achieve expected social status. To achieve different aspects of social welfare, due to Authors’ opinion, is the essential orientation of the social work. In the context of the social work mission the Authors describe it’s principles: humanism, justice, informed consent, the necessity to tell the truth, confidentiality, private character of communication etc.