A type of highly repeated DNA sequences present in the genome of Vicia faba was detected by digestion its nuclear DNA with FokI endonuclease and fractionating the digests on polyacrylamide gels. Four fragments of 59, 108, 177 and 246 bp of the FokI repeated sequences were collected from the gels and their primary structures were determined by the method of Maxam and Gilbert. These repeated DNA sequences were shown to be a multiple tandem array of a 59 bp sequence element. And its nucleotide sequence was almost completely conserved among all the sequence members of each the size class and also among these classes. This sequence element consists of a duplet of an about the duplet has an incomplete dyad symmetrical structure.