This study aimed to explore the key components of total flavonoids from Lamiophlomis Herba(LH) against rheumatoid arthritis (RA),which can elucidate the active components of LH against RA.In this work,the fingerprint of 13 batches of the total flavonoids from LH was established,including eight common peaks,of which three were identified.Based on the effect of 13 batches of total flavonoids from LH on the activity of fibroblast-like synoviocytes (FLS),the spectrum-effect relationship was established for the anti-RA effect of total flavonoids from LH.The results showed that luteoloside and luteolin were key components of total flavonoids from LH against RA.Then,the component knockout technique was used to investigate the anti-RA efficacy of the luteoloside component in the total flavonoids from LH,and the effects of luteoloside and luteolin on FLS cell viability were compared.The results showed that luteoloside and luteolin could significantly inhibit FLS cell viability (P<0.01),and there was no significant difference between their inhibition rates. Because the HPLC spectrum of total flavonoids form LH showed that the content of luteoloside was higher than that of luteolin,luteoloside is a key component of total flavonoids from LH against RA.This work can provide a certain reference for the clinical application of LH in the treatment of RA.