A field experiment, designed to have six treatments, i.e. CK (no fertilizer and/or manure applied); HF (chemical fertilizer); ZH (composted pig manure and chemical fertilizer); JHB (straw, chemical fertilizer and straw mate); ZHJ (composted pig manure, chemical fertilizer and straw); ZDH (composted pig manure based organic-inorganic complex fertilizer and fertilizer) was conducted to explore effects of application of composted pig manure and straw on population, genera and structure of the soil nematode community in the field. Results show that a total of 22 genera of nematodes of 11 families under 4 orders were found and identified in the six treatments, including 9 genera of bacterivores, 5 genera of fungivores, 4 genera of plant-parasites, 4 genera of omnivores-predators. The total number of nematodes was significantly higher in JHB, ZHJ and ZDH than in CK and HF, while no significant difference between HF and CK. Treatment ZHJ increased the abundance of bacterivores, but inhibited reproduction of phytophagous Tylenchus and Helicotylenchus. All the five treatments, except ZDH, were significantly lower than CK in abundance of plant-parasites. JHB, ZHJ and ZDH were significantly higher than CK in Nematode Channel Ratio (NCR), indicating that in the fields under organic farming, decomposition of the soil detritus food web relies mainly on bacteria. CK, JHB, ZHJ and ZDH was significantly higher than HF in Mature index (MI), indicating that the application of chemical fertilizer only brings about greater disturbance to the soil environment. No significant difference was found between the six treatments in Shannon-Wiener index (H´), Dominance index (λ), Evenness index (J) and Wasilewska index(WI). In all the five fertilized treatments, the c-p 2 group of soil nematodes was the highest in proportion, and was followed by the c-p 3-5 group, and the c-p 1 group the lowest. Comprehensive analysis of nematode trophic groups, community structure and ecological index indicates that JHB and ZHJ were the optimal fertilization modes.