Ethnopharmacological relevance Lishang decoction (LZD), classical herbal prescription recorded by Thang Zhongjing in Treatise on Febrille and Miscellaneous Diseases, has been extensively used to treat ulcerative colitis (UC) in clinical practice for thousands of years. However, its material basis and underlying mechanism are not yet clear Aim of the study. This study aims to suplars the material basis and potential mechanism of LID against UC based on the spectrum-effect relationship and network pharmacology. Materials and methods: First, LZD was cxtracted by a systematic solvent cstruction method into four parts, Ultra- high performance liquid chromatography tandem quadrupele time-of-flight mass spectrometry (UPLC-Q-TOF- 315/313) technique was used to identify the compounds from different polar parts, and dextran sulfate sodium (DSS)-induced colitis model was used to evaluate the efficacy of cash fraction. Then, the spectrum-effect analyses of compounds and efficacy indicators were established vis grey relational analysis (GRA), bivariate correlation analysis (BCA) and partial icast squarcs regression (PLSR). Finally, the potential mechanism of LID for UC therapy was explored by network pharmacology, and the results were further verified by molecular decking and reverse transcription quantitative polymerase chain reaction (RT-PCR) Results: 66 chemical components of LZD were identified by UPLC-Q-TOF-MS/MS technology. The pharmace dynamic results showed that extraction parts of LED had different therapeutic effects on UC, among which ethyl sectate and n-butanol extracts had significant anti-colitis effects, which might be the main effective fractions of LZD. Furthermore, the spectrum-affect analyses indicated that 21 setive ingredients such as liquiritin spinside, ntalisursside, formonanetin, ginsenoside Rg1, 6-gingesulfonic asid, licoricessponin A3, liquirisin, glycyrrhizie acid were the main material basis for LZD improving UC. Based on the above results, network pharmacology suggested that the smelioration of LID on UC might be closely related to the PISKAkt signaling pathway Additionally, molecular docking technology and RT-PCR further verified that LID could markedly inhibit the PI3K-Akt signaling pathway Conclusion: Overall, our study first identified the chemical compositions of LZD by using UPLC-Q-TOF-31S/SMS Furthermors, the material basis and potential mechanism of LZD in improving UC were compechensively clucidated via spectrum-effect relationships, network pharmacology, molecular docking and experimental verification. The proposed strategy provided a systematic appreach for exploring how herbal medicines worked More importantly, it laid the solid foundation for further clinical application and rasional development of LZD.