An abridged carboxylesterase E4 (CbE E4) gene was cloned from the peach-potato aphid, Myzus persicae, by reverse transcription-PCR and subcloned into the expression vector pET28b. The abridged CbE E4 gene was successfully expressed in E. coli BL21 (DE3). The recombinant CbE E4 hydrolyzed beta-naphthyl acetate and Carbaryl by 64% within 2.5 h, Malathion by 80% within 1.25 h. However, the hydrolysis of other pesticides (Dichlorovos, Parathion, Pirimicarb and Deltamethrin) was not detected.