Inflammatory responses after intracerebral hemorrhage (ICH) contribute to severe secondary brain injury, leading to poor clinical outcomes. However, the responsible genes for effective anti-inflammation treatment in ICH remain poorly elucidated. The differentially expressed genes (DEGs) of human ICH were explored by online GEO2R. Go and KEGG were used to explore the biological function of DEGs. Protein–protein interactions (PPI) were built in the String database. Critical modules of PPI were identified by a molecular complex detection algorithm (MCODE). Cytohubba was used to determine the hub genes. The mRNA-miRNA interaction network was built in the miRWalk database. The rat ICH model was applied to validate the key genes. A total of 776 DEGs were identified in ICH. Go and KEGG analyses indicated that DEGs were mainly involved in neutrophil activation and the TNF signaling pathway. GSEA analysis presented that DEGs were significantly enriched in TNF signaling and inflammatory response. PPI network was constructed in the 48 differentially expressed inflammatory response-related genes. The critical module of the PPI network was constructed by 7 MCODE genes and functioned as the inflammatory response. The top 10 hub genes with the highest degrees were identified in the inflammatory response after ICH. CCL20 was confirmed as a key gene and mainly expressed in neurons in the rat ICH model. The regulatory network between CCL20 and miR-766 was built, and the miR-766 decrease was confirmed in a human ICH dataset. CCL20 is a key biomarker of inflammatory response after intracerebral hemorrhage, providing a potential target for inflammatory intervention in ICH.