DNA barcoding was proposed as a method for recognition and identification of eukaryotic species through comparison of sequences of a standard short DNA ftagment-DNA barcode ftom an unknown specimen to a library of reference sequences ftom known species. This allows identifying an organism at any stage of development ftom a very small tissue sample, ftesh or conserved many years ago. Molecular identification of plant samples can be used in various scientific and applied fields. In this review, the authors present an overview of DNA barcoding and its application to agriculture. the authors introduced an international project that was formally initiated by the establishment of the Consortium for the Barcode of Life (CBOL) since 2004, which aimed to develop a standard protocol for DNA barcoding and to construct a comprehensive DNA barcode library of all eukaryotes, including 5 million specimens of 500,000 species. the authors also outlined some research in Vietnam applied nucleotide sequences to identify species and subspecies for many biologically and economically valuable plants in which the team was one of the first group paid much attention to this field. Rice was the first object in the research, the authors used nucleotide sequences of ORF 100 in chloroplast to distinguish 31 cultivars of glutinous rice growing in North Vietnam. Extension to native cultivated plants in Vietnam, several groups of economically valuable flower and medical plants including Cymbidiums. Paphiopedilum. Dendrobium. Phaenopsis. Panax. Discorea were used for sequencing their ITS and matK genes and comparison with GenBank database to point out special differences of the cultivar in Vietnam and the remain of world.