This paper reports on an experimental practice of a therapy "musical rhythm therapy", which is named and has been developed by the writer through his long teaching experience in the area of early childhood education, to remedy autistic children. The writer was motivated to develop this therapy in 1978 when the handicapped children's education became compulsory at public schools. In recent years, the number of kindergartens and nursery schools which play a leading role in the handicapped children's education is increasing. But the special education programs for those handicapped children have not been well established yet in the area of early childhood education, hence there is a confusion among kindergarten and nursery school teachers who do not have any educational background in that area. Thus the writer intends to improve the special education programs for the handicapped children and also to help the teachers in the area of special education for the future by reporting the cases of a clinical study of the musical rhythm therapy. Disappearing of fixation or obsession and forming of better living habits, though it had been very gradual, had been observed among the autistic children who underwent the musical rhythm therapy as its therapeutic value. In one case, for example, the child was obsessed with numeral letters, hence everything which had numeral letters on it had to be removed from the therapy room. However, of course, it was nearly impossible to remove even the numeral letters on the channel of the television set in the room for each therapy. In another case, the child was obsessed with outside signs and just called out the name of the stock company "Yamaichi Shoken" whenever he saw outside signs. In both cases, however, the children started showing their interests toward the subjects which the writer assigned instead of being obsessed with numeral letters and with outside signs after they underwent a number of the musical rhythm therapies. Thus the writer found the therapeutic value of the musical rhythm therapy in both cases. The major points of this study, the writer wants to emphasize, are as follows: 1. Teachers will be able to learn the musical rhythm therapy if they can master the basic methodology of the music therapy. 2. The priecipal goal of the therapies to remedy autistic children should be to help them to regain their normal relationships with people and living experiences, therefore the therapeutic value of the musical rhythm therapy should exist in improving of the children's basal living habits and competences to adapt themselves to their schools and society.