This study investigated the therapeutic mechanisms of Ranunculus ternatus Thunb.against ulcerative colitis (UC) using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) integrated with network pharmacology.A 3% dextran sodium sulfate (DSS)-induced UC mouse model was established to evaluate the efficacy of R.ternatus extract through assessments of body weight,colon length,and histopathological changes.Chemical constituents of R.ternatus extract were identified via UHPLC-MS/MS,and potential active compounds were screened using network pharmacology criteria.An "active ingredient-target" network was constructed,followed by GO functional enrichment and KEGG pathway analyses to identify key components,targets,and mechanisms.Treatment with R.ternatus extract (100 or 200 mg/mL) significantly alleviated DSS-induced weight loss,colon shortening,and histopathological damage.UHPLC-MS/MS identified 75 chemical constituents in R.ternatus extract,with phenolic acids (30.46%),alkaloids (22.96%),organic acids (15.81%),and flavonoids (10.72%) being the major classes.Network pharmacology analysis predicted 10 active compounds and 219 targets,enriched in 169 GO terms and 29 KEGG pathways.The therapeutic effects of R.ternatus against UC may involve key active components such as apigenin,mulberrin,and medicarpin,targeting Caspase-3,heat shock protein 90 alpha family class A member 1(HSP90AA1),and SRC proto-oncogene (SRC) to modulate biological processes including cellular transcription,immune metabolism,and inflammatory responses,thereby exerting anti-inflammatory effects.