Abstract: Community structure of natural enemies in the pear orchards treated with different pest management was investigated in Dazhong orchards, Beijing. The natural enemies, including 25 principal species belonging to 18 families, 6 orders were indentified. Much more predators and parasitoids were found in the tree crown and surface ground, respectively. Predator and parasitoid species accounted for 74% and 26% of the total natural enemies, respectively. Number of predators collected from the tree crown in the experimental orchards treated with pesticides for three times was significantly higher than that in the conventional orchards received chemical pesticides above 8 times, population size of parasitoids obtained from surface ground in the experimental orchards was also bigger than that in the conventional orchards. The total number of natural enemies in the experimental orchards was more than that in the conventional orchards. Population size of natural enemies decreased with more times of chemical pesticide spraying. Shannon index and Pielou index of the natural enemy community from tree crown of the experimental orchards were obviously bigger than those of the conventional orchard, but the species richness index and dominant index showed no significant differences between the experimental and the conventional orchards. These results provided practical evidences for the impacts of chemical pesticides and biological agents on the biodiversity of natural enemy.