【Objective】 Interactions between aboveground and belowground herbivores sharing the same host plant are regarded as the basic linkage between aboveground and belowground ecosystems, though they are separated in space. Much work has been done demonstrating that soil nitrogen availability affects the herbivores via plant by regulating chemical composition, such as nitrogen content of the plant. However, little has been reported on effects of the interactions between the two groups of herbivores on soil nitrogen. In this paper, a microcosm experiment was designed to investigate effects of the interactions between the herbivores on nitrogen distribution in the plant and labile nitrogen (microbial biomass nitrogen, dissolved organic nitrogen, ammonium nitrogen and nitrate nitrogen) in the soil. 【Method】In this study, Nilaparvata lugens and Hirschmanniella oryzae were selected as representative of the two groups, aboveground and belowground herbivores, respectively, and a pot experiment was designed to have two rates of Nilaparvata lugens , (zero or eight individuals per plant), and two rates of Hirschmanniella oryzae (zero or 500 individuals per pot), totaling four treatments and four replicates for each treatment. The soil used in the pot was first sterilized under 121℃ to kill all the native nematodes, and then was inoculated with the soil bacterial suspension prepared out of the original soil that had been deprived of soil nematodes, and put into a dark incubator for 60 days of incubation under indoor temperature to restore and stabilize microbial communities in the soil. Rice seedlings were transplanted into the pots after 30 days of seedling nursing in nutrient solution. Hirschmanniella oryzae and Nilaparvata lugens was inoculated separately on the fifteenth and twenty fifth day after rice seedlings were transplanted. Ten days after the inoculation of Nilaparvata lugens , samples of the plants and soil were collected. Plant samples were separated into shoot and root for measurement of biomass and nitrogen content, separately. Soil samples were analyzed, separately, for microbial biomass nitrogen, dissolved organic nitrogen, ammonium nitrogen and nitrate nitrogen. 【Result】Results showed that Nilaparvata lugens and Hirschmanniella oryzae negatively affected each other. Nilaparvata lugens tended to decrease shoot biomass, but did not affect much root biomass, while Hirschmanniella oryzae significantly reduced shoot and root biomass (p < 0.05). Nilaparvata lugens showed no significant effect on shoot and root nitrogen content, while Hirschmanniella oryzae significantly reduced root nitrogen content (p< 0.05), though they did not affect much shoot nitrogen content. Significantly interactive effects of aboveground and belowground herbivores on soil labile nitrogen were observed. In the absence of Hirschmanniella oryzae, Nilaparvata lugens significantly increased the content of microbial biomass nitrogen (p < 0.05) and decreased nitrate content significantly (p< 0.05), but did not have much effect on dissolved organic nitrogen and ammonium nitrogen, whereas in the presence of Hirschmanniella oryzae, they did not affect the content of soil labile nitrogen significantly. On the other hand, Hirschmanniella oryzae significantly and positively affected the content of microbial biomass nitrogen and total soil labile nitrogen (p < 0.05). 【Conclusion】 To sum up, the effects of the interactive suppressions between the aboveground and belowground herbivores on nitrogen content in shoot and root of the rice plants and on soil labile nitrogen are rather complicated. Moreover, compared with Nilaparvata lugens , Hirschmanniella oryzae tends to increase total soil labile nitrogen, which may in turn improve N-transformation-related ecological functions of the soil.