〔Abstract〕 To investigate the clinical phenotype and ADAM10 mutated locus of reticular acral pigmentation in a Chinese pedigree. The clinical data of 54 people from 5 generations of RAK family were retrospectively analyzed,and some members of the family and 100 unrelated healthy control blood samples were collected. All exons of ADAM10 gene were amplified by PCR and sequenced. All the affected patients showed a network of freckle-like pigmentation spots distributed on the back and neck of the hands and feet. Transcoding mutations in the 4 th exon of ADAM10 gene( c. 425-426 del GA; p. R142 Ifsx2) were detected in the probands of this family and in all patients,which was not detected in normal control family members or in non-related normal controls. A new mutation of ADAM10 gene may lead to the truncation of the protein that it encodes,resulting in the occurrence of disease.