OBJECTIVE: To probe into the potential mechanism of Erxian decoction in the treatment of breast cancer based on network pharmacology. METHODS: To collect the active components and effect targets of Erxian decoction through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform（ TCMSP）

and establish a database of breast cancer target by GeneCards

OMIM and CTD database. The intersection targets of Erxian decoction acting on breast cancer were extract

the Cytoscape Version 3. 7. 1 software and STRING database were respectively adopted to draw the network diagram of “active components of Erxian decoction-effect targets-breast cancer” and protein-protein interaction（ PPI）

Kyoto encyclopedia of genes and genomes（ KEGG） pathway enrichment analysis and gene ontology（ GO） function enrichment analysis were conducted by using R language-related software package

the effect intensity of active components and core targets was finally verified by molecular docking.RESULTS: Erxian decoction had 93 active components and 154 effect targets

breast cancer had 364 disease targets

there were 40 TCM component targets and breast cancer intersection targets

the herbal components with important effects were quercetin

kaempferol

isocorypalmine and β-sitosterol

and the key core targets were TP53

IL-6 and JUN. Totally 1 502 GO signaling pathways（ P<0. 05） and 101 KEGG signaling pathways（ P<0. 05） were screened out by GO functional enrichment analysis and KEGG pathway enrichment analysis

mainly involving the cancer pathways and PI3 K-AKT signaling pathway

etc. Results of the molecular docking showed a good binding between the compounds and effect targets. CONCLUSIONS: Erxian decoction has multi-component

multi-target and multi-pathway characteristics in the treatment of breast cancer

which can provide more support for follow-up studies.