Abstract: A strain of bacterium M3,capable of degrading malachite green efficiently,was screened out of sediment of a fish pond.Through 16S rDNA sequential analysis M3 was identified as Pantoea sp.When the concentration of malachite green was 0.5,1.0,2.0 and 5.0 mg·L^-1,its degradation rate was 97.54%,97.1%,100 % and 77.8%,respectively in 5 days of static incubation at 30 ℃.But the strain is unable to utilize malachite green as its sole carbon source.Glucose,NH₄NO₃ and KH₂PO₄/K₂HPO₄ can affect the degradation of malachite green.At the temperature ranging from 20 to 30 ℃,the strain can efficiently degrade malachite green with its degradation rate increasing with the temperature.