To further clarify the underlying mechanism of Kdm4a in premature senescent fibroblasts, we observed that Kdm4a can regulate H3K9me3 levels on tripartite motif containing 44 (Trim44), an important mediator of autophagy, by conducting ChIP‐seq assays and verified that Kdm4a downregulation promotes autophagy in premature senescent fibroblasts by increasing the H 3K9m3 modification of the Trim44 promoter, significantly suppressing premature senescence in fibroblasts, and ultimately reducing cardiac interstitial fibrosis. This evidence concerns the gene KDM4A and Interstitial cardiac fibrosis.