Abstract:【Objective】In order to investigate effects of organic manure on soil nematode community under jackfruit trees, a comparison study was conducted using grafted Malaysian No.1 saplings. 【Method】The experiment in the study was designed to have six treatments, i. e., CK (no fertilizer), 100CF (100% chemical fertilizer), 30OM (30% organic manure plus 70% chemical fertilizer), 50OM (50% organic manure plus 50% chemical fertilizer), 70OM (70% organic manure plus 30% chemical fertilizer), 100OM (100% organic manure). 【Result】 Results show that compared with CK and Treatment 100CF, all the other four treatments had varying significant effects of promoting biomass accumulation of the jackfruit saplings and increasing soil pH and organic matter in the soils. With increasing organic manure replacement rate, microbivorous nematodes and omnivores/predators increased in proportion, while plant-parasites decreased, the soil nematodes as a whole increased in diversity (H') and evenness (J') significantly, and the bacteria-dominated decomposition pathways in the soil food web did in proportion, too. β diversity analysis shows that the treatments varied significantly in nematode community structure, except for Treatments 50OM and 100CF, which were quite similar in that field. Dry weight of the shoot of the jackfruit saplings was significantly and positively related to abundance of bacterivores, organic matter and soil pH, while abundance of plant-parasites was negatively related to soil pH, organic matter, alkalyzable nitrogen and abundance of microbivorous ones, and abundance of bacterivores was significantly and positively related to soil organic matter and pH. 【Conclusion】Combined application of chemical fertilizers and organic manure can improve soil nematodes in diversity and evenness, balance the nematodes different in feeding habit in proportion, improve soil fertility and make the soil environment healthier and hence promote growth of the jackfruit saplings.