The essence and sources of threats to social security are discussed as well as the ways of ensuring social security. The methodological potential of the theory of human capital is shown. Models of human development and human security conceptions have been analyzed to substantiate the substitution of the individual-centred security conceptions for the state-centred one. A new definition of the security essence has been suggested: human security (rather than territorial security) is treated as being of paramount importance; security provided by armaments gives way to security guaranteed by stable human development. The meaning of security as a social phenomenon has been specified. The term “social security” is regarded as standing not just for protection against threats, but also for instrument of appreciating the degree of the social policy objectives realization. On the basis of social security indices threats to social security in modern Ukraine have been described. As main areas of life activities, social regulations have been named: modernization, civil selforganization, legitimation.