Abstract: According to the survey that rural market to hold bulk liquor extensively use of plastic bucket. Hexane was used to extraction solvent, extract dibutyl phthalate (DBP) from the plastic buckets containing bulk liquor by ultrasound-assisted extraction as well as dibutyl phthalate quantification was performed by high performance liquid chromatography (HPLC) . Extraction time, material/liquid ratio and extraction temperature were investigated with single-factor test. Response surface methodology based on Box-Behnken experimental desigen was used for process optimization. The optimal extraction conditions determined were extraction time of 52min, material/liquid ratio of 1 ∶40, extraction temperature of 49℃ . Under these conditions, the extraction volume of DBP was up to 32.21mg/kg, which was consistent with the prediction value. In the scope of 0.5 ～50.0mg/L, dibutyl phthalate had good linear relationship (R2=0.9998) , lowest detectable limit was 0.017mg/L. The relative standard deviation of standard experimental precision was 0.40%, the recovery of dibutyl phthalate was 99.68% and the relative standard deviation was 0.85% , the result showed that this extract method was accurate and reliable. This provided the basic data for food safety and the risk assessment of plasticizer.