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The correlation between the trophic structure, variety of nematode community and coverage of plant community in a desert steppe soil was studied under three grazing systems, namely, free-choice grazing, rotational grazing and rest-grazing respectively. The result is as follows: in regions of different grazing systems the species of nematode were similar, while the total number of nematodes was significant. The non-plant-parasitic nematode dominance was in following sequence under different grazing systems: close > rotational grazing > free-choice grazing. The correlation of non-plant-parasitic nematode with plant community coverage and standing vegetation was significantly positive, while that of plant-parasite was significantly negative. The Shanmon diversity index, Simpson diversity index, Nutrition diversity index (T), FF/BF, non-plant-parasitic nematode dominance can be seen as the sensitivity index when the desert steppe is influenced by different grazing systems.