Family of d case of musdtilar dystrophy with schizophtenia aird mental retardation are presented. The family are consisted of three brothers and a sister with their living parent. Two brbthfers of th^m show progressive muscular dystrophy with schizophrenia and mental retardation, and the youngest brother shows only the muscular dystrophy. The results of this study were as follows: 1. Progressive muscular dystrophy is considered as One of famtlial trait. 2. Progressive muscular dystrophy occurs in males. 3. Mental retardation seems to be undtrfly common in the Duchenne type of progressive muscular dystrphy. 4. In the progressive muscular dystrphy, there are no neurological symptoms nor Signs of central nervous system and the significant pathological findings are confined to the milscle.