The spatial and temporal structures of arthropod community in longan orchard were studied with 12 surveys. The arthopod community consists of 334 species belonging to 127 families of 21 orders in Insecta and Arachnoidea.There are 159 species within 69 families and 8 ordes of phytophagous insects,9 species within 9 families and 4 orders of scavenger inects, 47 species within 20 families and 7 orders of predacious insects,11 species within 9 families and 1 order of parasitic insects, and 108 species within 20 families and 1 order of spiders. They represent 31.21%, 27.15%, 25.49%, 1.28% and 14.87% in number of individuals and 47.60%, 2.69%, 14.07%, 3.29%， and 32.34% in number of species for phytophagous insects, scavenger insects, predacious insects, parasitic insects, and spiders respectively. There is an obvious stratificantion in the community structure. The species(groups) that are predominant in both top and bottom plant stracta are paratrechina flavipes , phintella versicolor , Psoeidae and Chalcidoidea. Lawana imitate, Tessaratoma papillosa , Cornegenapsylla sinica , Blaberidae and Ichneumonidae are predominant only in top plant stratum and Unapsis citri,Aleurocanthrs spiniferus, Culicoidea, Entomobryidae, Proctutrupoidea, Theridion xianfengensis and Chrysso lingchuanensis are predominant only in bottom plant stratum. On ground surface vegetation, the predominant species (groups) are Crematogaster biroi, Camponotus albosparus, Camponotus dolendus, Oxyopes sertatus, Entomobryidae, Culicoidea, Chalcidoidea, Broconidae and Ichneumonidae. Community structures in top plant stratum and in bottom plant stratum are similar for phytophagous and parasitic insects but very different for predacious insects and spiders. Population dynamics of all 5 sub-communities between January and October showed an early increase,peak,and then decline toward the end. Changes in spider populations are relatively small and peak occurs on April. Dramatic changes were observed in population dynamics of other subcommunities. The population peak on May for phytophagous insects,August for predacious insects,and between May and July for parasitic insects. Changes in population in ground vegetation community are smaller than that in the crown. The number of phytophagous insects shows a significantly correlation with the number of spiders.