In this paper, author tries to analyze complex character of the relation between law and morality in contemporary law philosophy. There are three approaches to the issue of relation between law and morality: natural law theory (identity thesis), positivist (separation thesis) and Anglo-American analytical jurisprudence (polarity thesis). The identity thesis-law and morality are basically identical, although basic principles of morality are subordinated to the positive legal rules; the separation thesis-law and morality are quite different system of norms: positive legal rules are completely deprived of any moral content; Polarity thesis - law and morality are different systems of norms which complement to each other. The polarity thesis is exemplified in theories of Herbert Hart and Ronald Dworkin's. At the logical level, polarity thesis overcomes and specifically synthesizes abstract character and reductionism of identity and separation thesis. At the socio-historical level, the polarity thesis is result of historical development of legal and political institutions.