Recently, a rapid movement of agricultural products with an extensive international trading and climate change have led to an increased attention to nematodes as having regulatory significance. With the increase of global dispersal of pests, new diagnosis methods are required for a rapid and reliable species and/or biotype identification to restrict introduction of the pests. Recently, novel molecular diagnostic techniques provide clues to solve taxonomic problems associated with conventional species identification. In this articles, we proposed various molecular diagnostic techniques to complement the limitation of morphological taxonomy.