Sugar beet cyst nematode ( Heterodera schachtii Schmidt) is one of the most destructive pathogens of sugar beet. Such that the lands infected regions with the nematode, has made the cultivation of this product endangered. Utilizing various agronomic and chemical methods, however, could reduce the damage of this nematode in some cases, but the environmental threats from each of these methods led to the continuation of searching for and exploring more efficient and more safe methods to manage sugar beet cyst nematode. According to the increasing of infected area to sugar beet cyst nematode in the country, the necessity of using resistant genotypes as one of the best methods for reducing the damage of this pathogen has been widely considered. In this research we used 11 genotypes of sugar beets to investigate the reaction of them to sugar beet cyst nematode. The experiment is conducted in two greenhouse and in-vitro parts and on the base of factorial experiment in randomized complete block design with five replications. . In greenhouse, the first test in order to investigate the reaction of sugar beet genotypes, sugar beet seedlings planted in pots at the four-leaf stage, were inoculated with 1000 eggs and second-stage larvae. In the second test, in order to investigate the penetration of second-stage larvae to sugar beet root, the seedlings planted in sterilized sands were inoculated with 1000 eggs and second-stage larvae of nematode. By using the growth indices of plant and nematode, the results of the first and the second tests were achieved in 10 and 5 weeks, respectively, after inoculation. The variance analysis of the data were calculated using SAS software and comparison of means was carried out using Duncan ' s test at one percent level. In in-vitro, in order to compare genotypes in terms of second-stage larvae penetration, laboratory germination of sugar beet seeds in PG 0B medium were used. In order to investigate the success of seedlings inoculation, petri dishes were observed under microscope on a daily basis and the formed cysts were observed. The reaction investigation of various sugar beet genotypes according to cyst nematode revealed that in terms of the number of formed cysts on the root, F-20314 and F-20710 were among the resistant genotypes with the lowest number of cyst, and Jam genotypes, I005, Jolgeh and Shirin genotypes were among the susceptible genotypes with the most number of cyst. Nematode created a meaningful effect on most of the growth indices of sugar beet genotypes including plant height, root length, plant dry weight and plant fresh weight, but the results of this investigation shows the low impact of cyst nematode on the grade of sugar of root. In other words, there was no meaningful difference between treatments. The results of analyzing variance of data suggested that there was a meaningful effect of nematode on the amount of chlorophyll and carotenoid in the inoculated leaves of sugar beet genotypes as reduction amount of chlorophyll and carotenoid were lowest and highest for Jam, F-20314, F-20543 and F-20656, F-20447. genotypes, respectively. The results from variance analysis and the comparison of the means of the number of formed cysts on the root of sugar beet genotypes under laboratory condition revealed a meaningful difference among treatments. It has to be said that the results from this experiment to a great extent were in accordance with the results of greenhouse experiments. It seems that by parallel study under greenhouse and laboratory conditions, we can separate resistant and susceptible genotypes to sugar beet cyst nematode. Keywords : Sugar Beet, Resistance, Cyst Nematode, Heterodera schachtii