OBJECTIVE To investigate the sex-specific effects of icariin on gut microbiota in aged mice and elucidate its regulatory mechanisms on microbial diversity, community structure, and metabolic functions. METHODS Young(2-month-old) and aged(24-month-old) male/female C57BL/6J mice were orally administered icariin(100 mg·kg·d^-1) or saline for 14 days. Gut microbiota profiles were analyzed via 16S rRNA sequencing, and metabolic pathways were predicted using KEGG annotation. RESULTS Icariin significantly increased α-diversity in aged mice(Chao1 index: +25%, P<0.05) and shifted β-diversity toward a younger-like pattern. At the phylum level, icariin reduced Bacteroidetes abundance while increasing Firmicutes(F/B ratio restored to youthful levels). Notably, Akkermansiaceae was enriched in aged female mice(4.1-fold). KEGG analysis revealed enhanced glucose metabolism and sphingolipid metabolism(3.2-fold upregulation in females). CONCLUSION Icariin ameliorates age-related gut dysbiosis in a sex-dependent manner, highlighting its potential for gender-tailored anti-aging interventions in traditional Chinese medicine.