Objective: Zuogui Wan? (ZGW) has been used as a typical prescription for tonifying kidney essence in traditional Chinese medicine. The objective of this study is to elucidate the phytochemical constituents of?ZGW?treated rat serum?(ZGWRS) ? using ultra?performance?liquid chromatography?electrospray ionization/quadrupole?time?of?flight high?definition mass spectrometry? (UPLC?ESI?Q?TOF?MS). Methods: ZGW was administered to rats, and the phytochemical constituents in rat serum were determined using UPLC?ESI?Q?TOF?MS. MetaboLynx analysis in negative ion mode was adopted to characterize the chemical constituents of ZGWRS. Orthogonal?partial least squares discriminant analysis? was applied for the discovery of constituents of ZGW that entered the serum of rats. The fertilized eggs collected from the same experiment were randomly divided into four groups, including the normal, 40 mmol/L glucose, 40 mmol/L glucose 5％ control rat serum, and 40 mmol/L glucose 5％ ZGWRS groups. They were cultivated at 37°C and 5％ CO2 in a saturated humidity CO2 incubator. The blastocyst rate and two?cell rate were used to evaluate the effects of ZGWRS on embryonic development. Results: Thirteen constituents were identified in the ZGWRS, among which sweroside, loganin, morroniside, loganic acid, and 8?epiloganic acid were from Fructus Corni?(Shan Zhu Yu). 5?Hydroxymethyl?2?furfural?glucuronide, 2?H?5?hydroxymethyl?2?furfural?glucuronide, 3?hydroxy?2,6,6?trimethyl?1?cyclohexene?1?carboxylic acid, and β?D?ribofuranuronic acid methyl ester triacetate were from Radix Rehmanniae Preparata? (Shu Di Huang). Coumaric acid was from Fructus Lycii?(Gou Qi Zi). Kaempferol?3?beta?O?glucuronide and cuscutamine were from Semen Cuscutae?(Tu Si Zi). The embryonic development was significantly inhibited using 40 mmol/L glucose. Compared with the normal group, the blastocyst rate of the glucose group was decreased. The blastocyst rate of the 40 mmol/L glucose 5％ ZGWRS group was significantly higher than that of the glucose group, indicating that ZGWRS negates the effect of glucose on mouse embryonic development. Conclusion: The results verified that a rapid and robust UPLC?ESI?Q?TOF?MS?based platform had been successful for identifying multiple constituents of ZGW. ZGWRS is rich in active constituentsof iridoid glycosides. The results of this study also showed that ZGWRS could negate the effect of glucose on mouse embryonic development.