OBJECTIVE：To study the intervention effects of Huan gqi injecti on on leucopenia model mice. METHODS ： Kunming mice were randomly divided into normal group ，model group and drug group ，with 8 mice in each group. Model group and drug group were given intraperitoneal injection of cyclophosphamide to induce leukopenia model. Normal group was given intraperitoneal injection of equal volume of sterile water. After modeling successfully ，normal group and model group were given intraperitoneal injection of equal volume of sterile water ；drug group was given intraperitoneal injection of Huangqi injection 0.04 mL/10 g，once a day ，for consecutive 7 d. Based on the detection of blood routine indexes （leukocyte，lymphocyte，neutrophil， monocyte count ）of mice in each group ，the metabolites in serum were analyzed by LC-MS. Principal component analysis （PCA）， partial least squares discriminant analysis （PLS-DA），orthogonal partial least squares-discriminant analysis （OPLS-DA），HMDB， METLIN， KEGG and other databases as well as related literatures were used to identify the differential metabolites. The metabolic pathways of differential metabolites were analyzed with MetPA online tools ，and the correlation of blood routine indexes and differential metabolites were analyzed on the basis of Pearson correlation coefficient. RESULTS： Compared with normal group ， blood rountine indexes of model group were decreased significantly （P＜ 0.01）. Compared with model group ，above blood r ountine indexes of drug group were all increased siginificantly （P＜0.01）. LC-MS chromatogram of serum samples in normal group and model group were significantly different ，and LC-MS metabonomics data of serum samples in drug group were similar to those of normal group. Multivariate statistical analysis and correlated database analysis revealed that compared with normal group ，serum contents of 17 metabolites as L-isoleucine，eicosapentaenoic acid were increased significantly in model group ，while the contents of 4 metabolites as spermidine were decreased significantly （P＜0.05 or P＜0.01）. Compared with model group ，Huangqi injection could reverse the serum contents of 9 metabolites in mice ，such as citric acid ，L-proline，acetylcarnitine，L-isoleucine， L-phenylalanine，sphingosine-1-phosphate，lysophosphatidylinositol，eicosapentaenoic acid and linoleic acid （P＜0.05 or P＜ 0.01），which were associated with linoleic acid metabolism ，biosynthesis of phenylalanine ，tyrosine and tryptophan ，and phenylalanine metabolism （metabolism pathway influential values were all higher than 0.1）. Correlation analysis showed that there was a significant correlation between blood routine indexes and the contents of D-sphingosine，linoleic acid and citric acid in model group（the absolute values of r were generally greater than 0.5）. CONCLUSIONS ：Huangqi injection can increase the counts of leukocytes，lymphocytes，neutrophils and monocytes in leucopenia model mice. The increase of leukocytes may be related to linoleic acid metabolism ，biosynthesis of phenylalanine ，tyrosine and tryptophan ，and phenylalanine metabolism.