Xiaoer Huanglong Granule is the only Chinese Patent Medicine widely used for treating attention deficit hyperactivity disorder. However, not much is known on the bioactive components and pharmacokinetics of Xiaoer Huanglong Granule even after it was successfully introduced into clinical use. This study analyzed the components in the medication and rat plasma after oral administration with the help of UNIFI platform and Masslynx. A total of 119 and 37 components were detected in the medication and plasma, respectively, using ultra performance liquid chromatography - tandem mass spectrometer. We established a rapid and sensitive simultaneous determination of 1 triterpene saponin, 3 monoterpene glycosides, and 3 lignans in rat plasma by solid-phase extraction. The determination was accomplished within 7.50 min via gradient elution. The values of lower limit of quantification were validated at 0.08 ng/mL for tenuifolin, 0.8 ng/mL for lactiflorin, 1.828 ng/mL for albiflorin, 2 ng/mL for paeoniflorin, gomisin B, and gomisin D, 10 ng/mL for schisandrin. The results from validations of other methods were all acceptable (RSD ≤ 14.94%). This is the first report on the identification and pharmacokinetics studies of components in Xiaoer Huanglong Granule. Moreover, the pharmacokinetic behavior of lactiflorin was studied for the first time. This article is protected by copyright. All rights reserved.