A prominent way of explaining how race is socially constructed appeals to social positions and social structures. On this view, the construction of a person’s race is understood in terms of the person occupying a certain social position in a social structure. The aim of this paper is to give a metaphysically perspicuous account of this form of race construction. Analogous to functionalism about mental states, I develop an account of a ‘race structure’ in which various races (Black, White, Asian, (...) etc.) are functionally defined social positions. Individual persons occupy these social positions by ‘playing the role’ characteristic of those positions. The properties by which a person plays a race role, are the realizers for one’s race. I characterize the social construction of a person’s race in terms of a realization relation that satisfies a ‘subset’ condition on the social powers of raced persons. Races, on this view, are functionally defined, multiply realizable social kinds. The final section of the paper outlines some explanatory benefits of the account. (shrink)