Abstract: In 1995 , a new esterase phenotype was found in a population of Meloidogyne javanica infecting tobacco in Lunan County of Yunnan Province , and the Rf value is 0. 47 and 0. 59 respectively. Morphological characters and differential host test suggested that the population belongs to M. javanica. However , the esterase phenotype was found to be different from that of M. javanica reported so far to absent a band ( Rf = 0. 55) . The new esterase phenotype is here designated as J2 for M. javanica. The possibility of a subspecies identity to accommodate the population with the new esterase phenotype is discussed.