Characteristics of pyrethriod-degrading strain Sphingobium sp. JZ-1 and its crude enzyme extract degrading pyrethriod were investigated in this experiment. The strain was capable of degrading a wide range of pyrethroid pesticides, which followed a descending order of permethrin > fenpropathrin ≈ cypermethrin > cyhalothrin > fenvalerate > deltamethrin > bifenthrin in degradation rate. No chiral selectivity was observed in biodegrading pyrethroid isomers. The initial reaction of Sphingobium sp. JZ-1, in degrading cypermethrin was to break carboxylic acid ester bonds under the catalysis of permethrin hydrolase yielding equimolar amounts of dichloroving acid (DCVA) and 3-phenoxybenzaldehyde, which was then oxidized into phenoxybenzoic acid. The pyrethroid hydrolase in Sphingobium sp. JZ-1 was expressed without pyrethroid induction.