Bioremediation of metsulfuron-methyl contamined soil with S113(Methylopila sp.)was studied under laboratory conditions. S113 was capable of utilizing metsulfuron-methyl as its sole carbon source for growth and degrading 98.38% of the 50 mg L^-1 metsulfuron-methyl within 72 h. Addition of S113 could prominently accelerate degrading of metsulfuron-methyl. When S113 was inoculated into the soil at a rate of 10 8 cells g^-1 dry soil,76.9% of the metsulfuron-2methyl(10 mg kg^-1 dry soil)in the soil was degraded after 30 days,whereas only 11.9% was degraded in CK.When inoculation rate decreased to 105 g^-1 dry soil,the action of S113 degrading metsulfuron-methyl in soil was not distinct,showing that degradation rate was related positively to the amount of inoculation,When metsulfuron-methyl was low in concentration,S113 was effective. When the concentration of metsulfuron-methyl was increased to 50 mg kg^-1,metsulfuron-methyl degradation rate was only 39.6%. Soil temperature also affected metsulfuron 2methyl degradation rate1 When it was 30℃,the rate reached 75.9% in 30 days,whereas when it was 25℃ and 20℃,the rate was lower to 53.5% and 2319%,respectively. Pouring S113 solution around the roots with S113 solution could mitigate the inhibitive effect of metsulfuron-methyl at 40 or 80μg kg^-1 on maize growth to a varying degree. When the concentration of metsulfuron-methyl increased to 120μg kg^-1,the mitigating effects were not distinct. The findings suggest that arti-ficial inoculation of S113 could effectively degrade metsulfuron-methyl in soil.