Abstract: The article Introduced the conditio ns and the methods to assay DDVPand O,O -Dimethyl -O -(p -ni-trophenyl)thionophosphate the pesticide residues invegetables by means of botani cal esterase.The activity of the en-zyme was shown by enzymatic reaction rate to take the place of the old actio n balance method.O,O -Dimethyl -O -(p -nitrophenyl)thionophosphate restrained the enzyme ’ s activity by 50～100times through th e additionof activa-tor.It constructed the enzyme ’ s controlling equation of DDVP and O,O -Dimethyl -O -(p -nitrophenyl)thionophosphate,with the minimal d etectable concentrationas 0.01ppm and0.166ppm.

Key words: Botanical esterase , Pesticide residue