【Aim】This study investigated the inhibitory effects of Callicarpa nudiflora leaf extract on the seed germination, stem cutting rooting, and potted plant growth of Mikania micrantha and analyzed the rhizosphere microbiome, aiming to reveal the potential ecological mechanisms of the allelopathic effects.【Method】This study investigated the allelopathic effects of 75% ethanol extract from C. nudiflora leaves on the seed germination, stem cutting rooting, and potted plant growth of M. micrantha and analyzed the rhizosphere microbiome to elucidate underlying mechanisms.【Result】(1) The 0.1% extract from January-harvested leaves (LY-H) exhibited the strongest inhibition on seed germination, reducing the germination rate, germination energy, and germination index by 77.1%, 76.2%, and 74.3%, respectively (p<0.01), compared with the control group (CK), with a synthetical allelopathic effect index (SE) of ?0.76. (2) The 0.1% extract from July-harvested leaves (XY-H) suppressed stem cutting rooting, decreasing the root number and length by 68.7% and 57.6%, respectively (p<0.05), with a SE of ?0.632. (3) In pot experiments, LY-H treatment reduced the total bolting length and stem weight of M. micrantha by 50.0% and 38.3%, respectively (p<0.05), showcasing persistent inhibitory effect. (4) The rhizosphere microbial analysis revealed that treated groups showed decreased abundance of nitrogen-fixing bacteria (e.g., Rhizobium) and nitrifying bacteria (e.g., Nitrospira) (p<0.01) and increased abundance of soil-remediating bacteria (e.g., Pseudomonas), suggesting that microbiome remodeling may indirectly enhance allelopathy by limiting nitrogen availability.【Conclusion】C. nudiflora leaf extract suppresses the growth of M. micrantha through dual pathways of allelochemical action and microbial regulation. The findings provide a novel eco-friendly strategy for invasive plant management.