Background: The MAPK/Erk signaling pathway is a classic pathway in cell proliferation. Our former study showed that keloid tissue revealed a higher proliferation level than physiological scars and normal skin. As a natural metabolite of estradiol, 2‐methoxyestradiol (2ME2) showed an inhibition proliferation effect on tumor cells. Aim: In this study, the treatment effect of 2ME2 and its potential mechanisms are explored. Methods: Six keloid patients and six non‐keloid patients were randomly selected from the Department of Plastic Surgery at our hospital during June 2021 to December 2021. Six groups were established: normal skin fibroblasts (N); keloid fibroblasts (K); keloid fibroblasts treated with 2ME2 (K + 2ME2); keloid fibroblasts treated with dimethyl sulfoxide (DMSO) (K + DMSO); keloid fibroblasts treated with doramapimod (K + IN); keloid fibroblasts treated with doramapimod (p38 inhibitor) and 2ME2 (K + IN+2ME2). The fibroblast activity and key factor expression of the MAPK/Erk signaling pathway were measured. Results: In the results, 2ME2 significantly inhibited keloid fibroblast activity and key factor expression (except STAT1). Conclusion: The proliferation levels were reduced by both the p38 inhibitor and 2ME2, indicating 2ME2 may achieve an antiproliferation effect by targeting p38 in keloid fibroblasts. [ABSTRACT FROM AUTHOR]