<p>In recent years, as the demand for research on special education has risen, various researches have been accumulated in a wide range of areas. Studies have also been performed from a point of view of the sociology of education. However, the existence of “children with disabilities” still assumed as axiomatic, and there have been few studies examining how this is achieved in interactions. Therefore, this article investigates the forms of interaction through which a child comes to be regarded as “child with disability” through an examination of audiovisual data showing educational practices in a school for children with mental disabilities. The author’s concern about forms of interaction does not aim to formulate principles which are not in touch with the realities in special educational practices, but rather to offer an effective viewpoint about “educating children with disabilities.”<br><br>The article consists of five sections. The first section describes the contemporary situation of special education, and shows the concern of this article. The second section points out that “doing be a child with disabilities” is first created by interactions with asymmetric characteristics, and then reviews some studies which can be seen as discussing the style of behavior or forms of interaction in the category of disability. Concretely, the author surveys the arguments of “stigma” (E. Goffman), “cutting out operation” (D. Smith) and “assumption of individual reality” (K. Sakamoto). In particular, this article is heavily influenced by the formulation offered by Sakamoto.<br><br>The third section provides a concrete analysis. It deals with two scenes from a second-grade art class. When the class comes to an end, one child begins to cry, beating his face. According to the homeroom teacher, the child has autism and intellectual disabilities, and has not yet acquired language. The author examines two scenes, paying attentions to how the participants perform description practices and how teacher will be “doing teacher in school for children with mental retardation.” The analysis clarifies the following. From the analysis of scene 1, (1) the teachers assumes an “assumption of individual reality” for the child by achieving his “intention” through the description practices, (2) at the same time they achieve the reality that the child cannot acquire language, (3) they display “main teacher” or “assistant teacher” though a distribution of the rights and duties tied to their utterances. In the analysis of scene 2, (1) though child is performing self-description practices with physical techniques, the teacher approves of the description of another teacher by ignoring him indirectly, (2) while the teachers accomplish “the end of the class” collaboratively, they also achieve “doing be a teacher” and “performing a class scene.”<br><br>The fourth section discusses forms of interaction about “doing be a child with disabilities.” From knowledge in analysis, it becomes clear that teachers organize the description of others with precedence in various ways. And this article concludes in a form that achieves “the assumption of individual reality” operationally. Furthermore, “educating a child with disability” is a practice which separate the child’s inability, and joins his abilities together.<br><br>The final section describes some problems encountered in the article.</p>