Objective To analyze the pathogenesy and mutation of X-linked juvenile retinoschisis (XLRS) 1 gene in XLRS families, and to provide the theory basis in directing gene diagnosis. Methods The mutation of XLRS1 gene code in two XLRS families were detected and screened by polymerase chain reaction (PCR) and DNA direct sequence determination. Results Pro193Ser mutation was detected in family 1. Conclusion Pro193Ser mutation could be found in XLRS families, which can be used for genetic consultation and prenatal gene diagnosis. (Chin J Ocul Fundus Dis，2004，20：149-151)