One of the major clinical characteristics of congenital stationary night blindness(CSNB)is dysfunction of rod photoreceptors of the retina.Rhodopsin,the photosensitive pigment of the rods,is essential for maintaining the normal function of rod photoreceptors.It is resonable to hypothesize that mutations or deletions of rhodopsin gene may be involved in the molecular defect of CSNB.To test this hypothesis,we are searching for rhodopsin gene mutations in patients with autosomal dominant CSNB.In this study,DNA fragments containing the coding sequences in exon 5 of rhodopsin gene were amplified by polymerase chain reaction(PCR)in 15 patients and 5 unaffected members from a large family with autosomal dominant CSNB.RFLP analysis of these DNA fragments demonstrated that in comparison with a control group of 12 normal persons,there is no obvious deletion in exon 5 of rhodopsin gene,and that mutations or deletions do not exist in codon 314,codon 347,and the third base of codon 313 as well as the first base of codon 348 of the rhodopsin gene in these CSNB patients,which suggest the molecular pathogenesis of autosomal dominant CSNB not involve mutations or deletions of these codons of the rhodopsin gene. (Chin J Ocul Fundus Dis,1993,9:66-69)