A triazophos degrading bacterium designated as mp-4 was isolated from soils that have long been subjected to organophosphate pollution.Strain mp-4 was identified as Ochrobactrum sp.based on its biochemical-physiological characters and the result of the 16 S rDNA homologue sequence analysis.Strain mp-4 can grow with triazophos as its sole carbon source and degrade it at a rate of 98.3% .The optimal growth temperature and pH for mp-4 are 30℃ and 6.6 respectively.At the temperature of 27~32℃ and pH of 7.5~8.8,mp-4 can degrade triazophos well.Field test results show that mp-4 can decrease the residue of triazophos in rice husk and brown rice by 91.9% and 100% ,respectively.