Many social theorists have understood Giddens' social theory (structuration theory) to be an attempt to integrate traditional sociological theories, and they have not been able to clarify what his real interests are. In this essay, through reading Giddens' social theory as a social theory of ‘being and time, ’ I will point out Giddens' unique interests and try to re-appraise his structuration theory. His unique interests lie in trying ‘to introduce an ontological view’ that denies the dominant of an epistemological view in traditional social science, and ‘to emphasize reversible time’ that contrasts with linear time in traditional social science.