In contemporary American sociology, many theories base themselves on George Herbert Mead's communication theory. However, his own theory has not completely analysed up to this day. This is because he was not a sociologist, but one of "the most original American pragmatists". Then we need to consider the inner relation between his theory and his basic philosophy, i.e. pragmatism. In this point of view, the purpose in this paper is to make the connection of them clear and to explain a significance of the present day on his communication theory. Making analyses of them, I intend to pay attention to a structure of "meaning" in his thought and to examine its problem from two points of view. The one is "time" and the other is "act", and both of them are important concepts on pragmatism. In these explanations, it will be clear that a communication process in his theory, that is symbolic interaction with "self" and "others", describes a constructing process of our everyday life-world, which is intersubjectively opened.