Abstract: For exploring the degradation of miticide F1050 by microorganisms, the plate methods and enrichment culture were progressed. Five strains of bacteria were obtained in soil by purification culture on the synthetic medium for miticide F1050, which were ZJU.01(Bacillus subtilis 69%), ZJU.02(Bacillus megaterium 99%), ZJU.03(Bacillus cereus 86%), ZJU.04(Bacillus cereus 92％), ZJU.05(Bacillus sphaericus 99%). Results of the microbial degradation showed that ZJU.02,ZJU.04 and ZJU.05 among those bacteria tested had special ability to degrade the chemicals in a series of culture medium with different volumes(10％ in total volume) of bacteria suspension while the concentration of the acaricide at 50 mg/L in the media. And the miticide has a promoted degradation process in soil by bacteria, the half-lives were 6.48 d, 6.74 d and 6.41 d respectively, compared with 29.88 d and 72.20 d in unsterilized or sterilized soil. There was no significant difference among the three dominant strains of miticide F1050.