This study, through examining the theory by Minoru Nishio (1889-1979), treats the way of grasping the actual state of students. In his idea, it is important for constructing Japanese language education to grasp the true figure of students' language concretely. "Ecology of Language", the term in his theory, expresses this. There were two aims why he grasped "Ecology of Language", as follows: (1) To build the region of Japanese language education study. (2) To improve our living language through Japanese language education. In addition, there were two steps to grasp it, as follows: (1) Observe and describe the actual fact of a living language ecologically. (2) Point out the problem of it analytically. In order to make Japanese language education systematic, he insisted we should grasp the true figure of students' language not only analytically but ecologically. It will be possible for us to make joints in the Japanese classes more obviously by means of grasping "Ecology of Language" Nishio's way.