Abstract: The determination of ultimate residue of fenvalerate in soybean and soil of soydean fild was carried out with gas chromatography. The residue was within the scope allawed by FAO/WHO when 8g/mu or 4g/mu of active ingredient of fenvalerate was applied, The residue dynamic equation of fenvalerate in Soybeen-plants and the soil was negtive exponential function, The Half-Life of fenvalerate in the soybean-plants was 2.56 d and 7.7 d in the soil.

Key words: fenvalerate, gas chromatography