An ultra high performance liquid chromatographic(UPLC) method was developed for the simultaneous determination of seven water soluble fluorescent whitening agents in medicinal composite films.The sample was extracted with 40% acetonitrile aqueous solution adjusted to pH 11.0 with triethylamine,and separated on a Waters ACQUITY UPLC BEH C18(100 mm×2.1 mm,1.7 μm) at 40 ℃ by gradient elution with acetonitrile-methanol solution(2∶3) and 10 mmol/L tetrabutylammonium bromide-methanol solution(5∶95,pH 8.0) as mobile phases at a flow rate of 0.2 mL/min.The detection wavelength was set at 350 nm.Results showed that there were good linear relationships for the analytes in corresponding concentration ranges with their correlation coefficients(r) of 0.998 6-0.999 7.The limits of detection(LOD) and limits of quantitation(LOQ) of the method were in the ranges of 0.17-1.29 μg/mL and 0.55-3.85 μg/mL,respectively.The average recoveries at three spiked levels ranged from 83.2% to 110%,with relative standard deviations(RSD) of 4.0%-9.7%.The detection results showed that two kinds of fluorescent whitening agents were detected in the polyester/aluminum/polyethylene medicinal composite film and paper/aluminum/polyethylene medicinal composite films at most,no fluorescent whitening agent was detected in other varieties.The method is simple,reliable and repeatable,and could be used for the determination of fluorescent whitening agents in medicinal composite films.