Abstract: By using community structural characteristic indices and principal component analysis, this paper studied the community structure and its dynamics of predatory arthropod in the jujube orchards intercropped with Astrugalus complanatus, Trifolium repen, Lotus comiculotus, and Medicago sativa. The results showed that in all test jujube orchards, spider and predatory insects were the predominant components of the predatory arthropod community, and their relative abundances were 48.3%~52.7% and 38.8%~44.4%, respectively. There were significant differences (P<0.05) in the mean density, diversity, and evenness of the most common predatory arthropod groups in the jujube orchards intercropped with different herbage species, with the sequence of intercropped with Lotus comiculotus> Medicago sativa>Astrugalus complanatu> Trifolium repens, but for dominant concentration index, the sequence was intercropped with Trifolium repens>Astrugalus complanatu>Medicago sativa>Lotus comiculotus. The average density of predatory spiders was significant higher (P<0.05) than that of predatory insects in all test jujube orchards. The individuals of Coccinellidae, Pentatomidae, inoccllidae, Chrysopidae, Thomisidae, Araneidae and Phytoseiidae played the dominant role in the community.

Key words: Permanently flooded rice field, Methane emission, Factor analysis, Ridged cultivation