In order to reveal the characteristics and growth of plants in desertification grassland in Ningxia, the niche breadth and niche overlapping of plants in the desertification grassland of Wujijuan, Yanchi county were measured by means of Levin’s niche breadth and Pianka niche overlapping indexes. The results showed that Lespedeza dazzurica and Laceris chinensis var. graminifolia had the widest niche breadth, and were the dominant species in 2010 in this region. In 2011, Lespedeza davurica, Heteropappus altaicus and Lereris chinensis var. grarninifolia became the dominant species because of the interspecific competition and rainfall and so on. Meanwhile, the results of niche overlapping in 2010 and 2011 showed that the species with wide niche breadth did not always have wide niche overlapping, and the niche breadth and niche overlapping did not show an obvious linear relation. Compared with 2010, the niche breadth and niche overlapping were wider on the whole in 2011, because the amount of the rainfall from July to August was much more than that in 2010, the plants grew better. The results above indicated that the amolmt of rainfall in.