OBJECTIVE：To study metabonomics of secondary components of Astragalus membranaceus injection on leukopenia model mice. METHODS ：The mice were divided into normal group ，model group ，A. membranaceus injection group （0.004 mL/g），secondary components low-dose ，medium-dose and high-dose groups （0.004，0.008，0.016 mL/g），with 7 mice in each group. Except for normal group ，other groups were given cyclophosphamide （80 mg/kg） intraperitoneally to induce leukopenia model. After modeling ，administration groups were given relevant medicine intraperitoneally ，and normal group and model group were given constant volume of sterile water for injection intraperitoneally ，once a day ，for consecutive 7 days. During the experiment ，the changes of body weight of mice were measured every 2 days. After the last administration ，the blood routine indexes [white blood cell （WBC），neutrophil（NE），lymphocyte（LY）and monocyte （MO）counts] of mice were detected by animal blood analyzer. UPLC-Q Exactive Orbitrap-HRMS combined with multivariate statistical analysis were used to analyze the metabonomics of mice serum. RESULTS ：Compared with model group ，body weight of mice in the secondary component low-dose group increased significantly on the 4th and 8th day of administration （P＜0.05），and the counts of WBC ，NE，LY and MO in serum of mice in secondary component groups increased significantly （P＜0.05 or P＜0.01）. Metabonomic analysis showed that the secondary components of A. membranaceus injection could significantly regulate the contents of 8 endogenous metabolites in serum， including spermidine ， uric acid ， citric acid ， nicotinamide， eicosapentaenoic acid ， linoleic acid ， erucamide and sphingosine-1-phosphate. Their effects involved linoleic acid metabolism pathway ，nicotinic acid and nicotinamide metabolism pathway and tricarboxylic acid cycle pathway. CONCLUSIONS ：The secondary components of A. membranaceus injection possess the effect of increasing white blood cells in leukopenia model mice ，the mechanism of which may be related to intervention of linoleic acid metabolism pathway ， nicotinic acid and nicotinamide metabolism pathway ，and tricarboxylic acid cycle pathway.