A sensitive method based on ionic liquid dispersive liquid-liquid microextraction(IL-DLLME) and high performance liquid chromatography with diode array detector(HPLC-PDA) was developed for the preconcentration and determination of seven naphthalenediols in environmental water samples.The ionic liquid,1 butyl 3 methylimidazolium hexafluorophosphate(［C4MIM］［PF6］) was used as extraction agent,and 8.0 mL of aqueous phase was selected.Some important factors affecting the extraction efficiency such as amount of ［C4MIM］［PF6］,pH value of aqueous phase,extraction time and salt concentration were optimized.The optimized conditions were as follows:150 μL［C4MIM］［PF6］,pH value of aqueous solution：5.0-7.0,vortex extraction time：3 min, sodium chloride：0.20 g/mL.Under the optimized conditions,the calibration curves of 7 naphthalenediols were linear in the certain concentration range with correlation coefficients not less than 0.997 7.The enrichment factor of this method was 57,and the detection limits of this method(S/N=3) were between 0.3 μg/L and 1.0 μg/L.The average recoveries of naphthalenediols at three spiked levels in negative environmental water sample ranged from 83.5% to 103% with relative standard deviations(RSD,n=6) of 1.1%-3.8%.The developed method is rapid,sensitive and environment friendly,and is suitable for the detection of trace naphthalenediols in environmental water samples.