Objective:To explore the differences of microenviroment between peri-implant tissue and oral mucosal tissue.Methods:The gene chip data GSE43744 was downloaded from the GEO database,bioinformatics tools were used to analyze the differentially ex-pressed genes between the peri-implant tissue and normal oral mucosal tissue in rat.Results:1315 differentially expressed important genes,including 797 upregulated genes and 518 downregulated genes,were screened out.Gene enrichment analysis showed that com-pared with normal oral mucosal tissue,the gene expression of innate immune activity,cell activation,inflammatory response,and func-tional expression related to external and bacterial stimuli in peri-implant tissue were significantly upregulated,while that of extracellular matrix tissue,adhesion,extracellular matrix polysaccharides,response to mechanical stimuli and response to toxic substances was sig-nificantly downregulated.Meanwhile,multiple molecular functions and biological pathways related to T cells were highly expressed,which may play an important role in the peri-implant microenvironment.In addition,PPI network was constructed,and screened 7 core genes including FCER1G,TYROBP,PTPRC,ITGB2,AIF1,EMR1 and RAC2,which may be target genes for studying peri-implant microenvironment.Conclusion:There is a significant difference of microenvironment characteristics between peri-implant tissue and o-ral mucosa.The target genes screened using PPI network may be the key to future research on the peri-implant microenvironment.