Objective To analyze the relationship between genotype and phenotype of vitelline macular dystrophia (VMD2) gene in a family with Best disease, and to provide the theoretical basis for gene diagnosis of Best disease. Methods Mutation in the coding regions and the promotor sequence of VMD2 gene from 10 members in a family with Best disease were screened by polymerase chain reaction (PCR) and direct DNA sequencing, and combined with a conformation sensitive gel electrophoresis (CSGE) approach, VMD2 gene screening was performed on 100 normal control individuals. Results In the 10 members, Trarr;C nucleotide change at the 223 base of exon 3 was detected in 9, including 6 with Best disease who was confirmed by ophthalmoscopy and electrophysiological examination in whom 2 were affirmed as having homozygote of this mutation. Other 3 young family members with VMD2 gene mutation only had abnormal electro-oculogram manifestations. Above mutation was not detected in the normal control individuals. Conclusions The phenotype and genotype of VMD2 in the family with Best disease is highly correlated. Mutation in VMD2 gene is the nosogenesis in this family. Mutation screening of VMD2 gene can be used for genic diagnosis and genetic consultation of Best disease. (Chin J Ocul Fundus Dis, 2006, 22: 86-89)