Purpose: To study the therapeutic effect of 3-O-caffeoylquinic acid (3-O-CQA) from Periploca forrestii extract (PFE) on collagen-mediated arthritis (CIA) in rats, as well as the potential underlying mechanism of action. Methods: PFE and 3-O-CQA were successively and intragastrically administered to CIA rats. Paw swelling, arthritic scores and H & E staining were used to evaluate the therapeutic effect of 3-O-CQA. Moreover, to determine the effects of PFE and 3-O-CQA on fibroblast-resembling synoviocytes obtained from arthritic subjects (RAFLS), the viability of RAFLS cultured in vitro was measured with MMT, while apoptotic lesions were analyzed by flow cytometry. The levels of IL-6 in CIA and RAFLS were determined by enzyme-linked immunosorbent assay (ELISA), while quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunoblotting were used to assess their mRNA and polypeptide levels, respectively. Results: PFE in 3-O-CQA ameliorated swelling and reduced arthritic scores in CIA rat model, and also decreased cytokine levels (p < 0.05). By decreasing mRNA and protein expressions, 3-O-CQA repressed the phosphotylation of STAT3 and JAK2 as well as the protein levels of IL-23 and RORyt (p < 0.05). Conclusion: The results of this study show that CIA and RAFLS are ameliorated in rats by 3-O-CQA in PFE through regulation of IL17/IL23 and Th17 cells. Thus, 3-O-CQA affords a therapeutic strategy for the management of collagen-induced arthritis.