The term "familiarity" is conceived, by Arsenian, as same as that of "being structured of situation."So far as we understand it in this way, it is a functional conception, not a phenomenal description. In this approach, I will take up the problem from its phenomenal aspects. Here I want to follow the process of the transformation of an unfamiliar space to a familiar one. This process may be expressed in behavior. This experimental approach shows that the transformation is expressed in decreasing of the amount and kind of responses within a given time.