〔Abstract〕 Objective To explore the influence of IL-6 secreted by cancer-associated fibroblasts(CAFs) on promoting the proliferation and invasion of ovarian cancer cells and the possible mechanisms. Methods CAFs and normal ovarian fibroblasts(NFs) were isolated and cultured respectively from epithelial ovarian cancer and normal ovarian epithelial tissues. Cell markers alpha-smooth muscle actin(α-SMA), E-cadherin were detected by Western blot and immunofluorescence. CAFs and normal ovarian fibroblasts(NFs) were collected and cultured, and their supernatants were used to establish an indirect co-culture system with ovarian cancer SKOV3 cells, including SKOV3 cells alone(SKOV3) group, SKOV3 combined with the supernatants of NFs(NFs) group and SKOV3 combined with the supernatants of CAFs(CAFs) group. Cell immunochemistry was used to detect the expression of alcohol dehydrogenase 1B(ADH1B) in SKOV3 cells co-cultured with the supernatant of CAFs or NFs. Before and after treatment with the methylation inhibitor 5-aza-2′-deoxycytidine(5-Aza-dC), methylation-specific PCR(MSP), Reverse transcription quantitative real-time PCR(RT-qPCR), enzyme-linked immunosorbent assay(ELISA), and Western blot were used to detect the mRNA level and methylation status of ADH1B, and the phosphorylation level of signal transducers and activators of transcription 3(p-STAT3).The cell counting kit-8(CCK-8) method and Transwell assay were used to investigate the effects of the IL-6 inhibitor LMT-286 and recombinant human interleukin-6(rhIL-6) on cell proliferation and invasion. Results The protein levels of α-SMA was highly expressed, however, CAFs and NFs cells almost lacked the E-cadherin protein. Compared with the SKOV3 and NFs groups, CAFs group exhibited significantly downregulated mRNA and protein expression of ADH1B. After treatment with 5-Aza-dC,ADH1Bmethylation was partially reversed, and the mRNA and protein expression of ADH1B increased in all groups. The phosphorylation level of STAT3 proteins was significantly reduced in CAFs group, while there were no significant changes in SKOV3 and NFs groups. Intervention with LMT-286 and rhIL-6 only inhibited or promoted the proliferation and invasion of cells in CAFs group, while there were no significant changes in SKOV3 and NFs groups. Conclusion CAFs can enhance the methylation ofADH1Bin ovarian cancer cellsviaIL-6/STAT3 pathway, and may promote the proliferation and invasion.