In order to provide a theoretical basis for the use of Macleaya fungicide to produce green vegetable,a field experiment was carried out to reveal the dynamics of Macleaya fungicide residue in pakchoi and soil.The results showed that spaying of 750 or 1500g/hm² Macleaya fungicide solution to pakchoi,Macleaya fungicide in pakchoi degraded quickly in the first 5 days and nearly degraded totally after 15 days;while Macleaya fungicide in soil degraded slowly in the first 7 days,then the degradation rate was accelerated,after there was no Macleaya fungicide residue in soil after 32 days.The residual half-life of Macleaya fungicide were 1.83d and 8.37d in pakchoi and soil,and the finally residues of Macleaya fungicide in pakchoi and soil were less than the MRL values 0.500 0 mg/kg.The results implied that Macleaya belong to easily degradable,non-polluting,high security plant source pesticides,which was suitable for widespread in agricultural production.