In this work the modern mechanisms defining complexity of management in modern social systems are analyzed. It is shown that the principal cause of modern complexity of management consists in management of not completely formalized technologies of activity of social systems of a great number. Modern feature of management in difficult social systems is essential influence of technologies of the market which essentially aren’t regulated by norms and institutes, and also essential influence of nature restrictions of cogitative possibilities of the person to operate-manage. Influence of poorly regulated technologies in the market can be reduced by use of network, organizational, collective, information and other developed technologies of maintenance of management and by use of methods integrating science. And reduction of influence of mental restrictions demands creation new cognitive technologies of the management, allowing dividing functions at thinking level.