An ultra high liquid chromatography-quadrupole orbitrap mass spectrometry（UHPLC/Q-Orbitrap-MS） combined with chemometrics was developed for the rapid analysis of absorbed components of Ziziphi Spinosae Semen in rat serum.A model for insomnia rat was established by intraperitoneal injection of para-chlorophenylalanine（PCPA）.After intragastric administration of Ziziphi Spinosae Semen aqueous extract for five successive days,the serum samples from the model group and the Ziziphi Spinosae Semen aqueous extract treatment group were collected.The protein was removed using Oasis PRIME HLB 96-well plates.The data was acquired by UHPLC/Q-Orbitrap-MS,and analyzed by chemometrics including principal component analysis（PCA）,orthogonal partial least-squares discriminant analysis（OPLS-DA） and variable importance in the projection（VIP） to screen different prototype compounds and metabolites.A total of 20 components were identified,including 11 prototype components and 9 metabolites.The developed method provides a basis for further study on the effective substances of Ziziphi Spinosae Semen for insomnia improvement.