A solid phase microextraction(SPME) probe based on graphene self assembly was prepared in situ,which was combined with GC-MS to develop a method for determination of toluene,ethylbenzene and o xylene in water.SEM characterization results showed that graphene on the probe prepared was uniformly and firmly bonded to the quartz fiber.The effects of extraction mode,extraction temperature,extraction time and salinity were optimized.Under the optimum conditions,three benzenes showed good linearity in the concentration range of 0.2-200 μg/L,with their linear coefficients(r2) of 0.998 7-0.999 6.The limits of detection of this method ranged from 0.001 2 μg/L to 0.004 2 μg/L with relative standard deviations less than 5%.Three collected samples were detected to observe benzene series pollution with different concentrations.The spiked recoveries ranged from 90.3% to 111%.This method could be used for the determination of benzene series in environmental water samples.