Based on the comparison of extraction efficiencies of two extraction methods and different organic solvents，an ultrasonic-assisted extraction procedure coupled with high performance liquid chromatography(HPLC) with UV detector was developed for the determination of 4-nonylphenol(4-NP) in soil.The results showed that the extraction efficiency of 4-NP in soil by ultrasonic-assisted extraction with dichloromethane was higher than that by the Soxhlet-extraction method.The results of ultrasonic-assisted extraction with different organic solvents demonstrated that the extraction efficiencies decreased in an order of dichloromethane-methanol(9∶1)＞dichloromethane＞methanol≈acetone. The recoveries of 4-NP in soil at three spiked levels of 10，20,40 mg/kg ranged from 91% to 94% with relative standard deviations(RSDs) of 4.3%-7.2%，and the detection limit of method for 4-NP was 2.0 μg/kg.The method was applied in the determination of 4-NP in soil samples collected from Guangdong Province，and the results showed that the concentrations of 4-NP varied from 5.3 μg/kg to 16 μg/kg by dry weight,which were lower than those obtained from the wastewater irrigated soil of Hebei Province.This method is rapid，sensitive，reproducible and suitable for the determination of 4-NP in soil.