Abstract: A novel bienzyme electode biosensor for rapid determination of carbamate and orgnophosphorus pesticides was developed.The sensor was prepared by co-immobilizing acetylcholinesterase(AChE) and choline oxidase(ChOx) on a Fe3O4/Au nano particles surface modified screen printed electrode (AChE-ChOx/Fe3O4/Au SPCEs).The modified enzyme electrode showed linear current response to acetylcholine in the range of 0.5 ~12.5 mmol/L.It was utilized for carbofuran and dichlorovinyl dimethyl phosphate detection with a linearity range between 0.05 and 1.00 μg/mL (R2＝0.977).The detection limit may reach 0.01 μg/mL and their recovery exhibited a range of 95% ~110 % in chinese cabbage.The method using biosensor may be matched with the traditional biochemical method with low cost, desertable and easy preparation, thus would be valuable for rapid detection of carbamate and organophosphorus pesticides.