Abstract: The results of dunamics about Acephate of different formulations showed:(1) Acephate could metabolize to Methamidophos and metabolic rate was affected by different formulations;(2) the half-life of Acephate in cabbages was 1.12~1.19 days,and the half-life of Methamidophos in cabbages was 1.53~1.76 days;(3) Acephate had higher Methamidophos residue risk in the crops,and the safe interval of acephate should be extended to 11days.