This paper outlines some molecular marking technology based on rDNA sequences and several DNA fingerprinting technology (RAPD, ARDRA, AFLP, REP/ERIC-PCR) used in classification, identification and diversity research in lactic acid bacteria. The principles, methods and progress in recent years of these technologies were also introduced. At the same time, this paper also compares the advantages and disadvantages of these methods. People should choose suitable method according to their purposes.