An autosomal dystrophic epidermolysis bullosa (DDEB) is a hereditary mechanobullous disease characterized by blistering of the skin and the mucous membrane. DDEB is caused by a heterozygous mutation in the COL7A1 gene encoding type VII collagen, the major component of anchoring fibrils, and phenotypically classified into several types. We experienced two boys with DDEB and examined the mutation analyses of the COL7A1 genes of the two patients and their fathers to clarify the relationship between the genotypes and phenotypes, that is, the mutation sites of COL7A1 gene and the clinical types of DDEB. The case 1 and 2 patients and their fathers revealed a heterozygous nucleotide G to A transition at position 6109 and 6082 in 73 exon of COL7A1, which resulted in a glycine to arginine substitution (G2037R and G2028R), respectively. G2037R found in the case 1 patient was a novel mutation. There was no clear relationship recognized between the two mutation sites in the COL7A1 gene and the clinical variations.