Abstract: The study is aimed to test the effect of Huangqin Tang (HQT) on serum metabolic profile in rats with ulcerative colitis, and explore its possible action mechanism for ulcerative colitis (UC) rats. The model of UC rats with cell immunoreactivity was made using a compound method (trinitrobenzene sulfonic acid plus ethanol). Rats were randomly divided into the control group, the model group, and HQT group. Ultra performance liquid chromatography tandem mass spectrometry (UHPLC-MS), principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were employed to analyze the metabolic profile among normal group, the model group, HQT group. Potential biomarkers were screened in the serum based on the variable importance projection (VIP) value > 1, P< 0.05. As compared with the normal group, 16 potential biomarkers such as valine, tryptophan, lactic acid and urea were found and identified in the serum of model group rats. As compared with the model group, a part of the biomarkers were restored nearly to a normal state after HQT administration for 10 days. Metabolomic analysis revealed that the HQT has a certain therapeutic effect in UC rats, and the mechanism may be related to regulation of lipid metabolism, amino acid metabolism and energy metabolism.