In Egypt, sugar beet is cultivated in 257667 faddans with an average production of about 18.593 tons per faddan 2007- 2008. Recently, reclaimed desert irrigated lands at West Nubaryia and El-Bostan regions has shown that sugar beet can be successfully grown under sandy soil area condition and is considered as an extended area for sugar beet production in Egypt. The most serious problem against sugar beet extension in new lands is root-knot nematode, Meloidogyne javanica which were reported as major nematode pests of sugar beet in Egypt. Importance of employed resistance nematode sugar beet genotypes (cultivars/hybrids) in infested areas has a great concern. The present study was carried out during the growing season 2007 - 2008 in Sabahia Agricultural Research Station, Alexandria, Egypt to study the activity of three different isozymes (esterase, amylase and peroxidase) in twenty seven sugar beet genotypes had different background in immune behavior (susceptible or resistance) to nematode Meloidogyne javanica to recognized biochemical marker for this trait. To facilitate the choice of resistance ones for planting in nematode contaminated areas and can be used in evaluative purposes breeding programs to identify resistant breeding materials. From the three studied isozymes only peroxidase may differentiate between susceptible or resistant sugar beet genotypes to root-knot nematode.