Esophageal squamous cell carcinoma (ESCC) is one of most common and deadly forms of cancer in the world.Recently, emerging studies have suggested that an aberrant microRNA (miRNA) expression signature exists in ESCC.In order to determine the involvement of microRNA (miRNA) in the development and progression of ESCC, the expression profiles of miRNA in 8 paired ESCC tissues and corresponding normal esophageal tissues were analyzed by miRNA microarray.Forty-three differential miRNAs including 27 downregulated and 16 upregulated miRNAs were found in ESCCs.In these miRNAs, we found that the miR-1 was significantly downregulated.Then, the expression of miR-1 was validated in 64 pairs of primary ESCC samples using SYBR-green quantitative PCR.The expression levels of miR-1 were significantly decreased, which was significantly correlated with tumor invasion and advanced stage (P =0.025 and P =0.035, respectively).In addition, functional assays demonstrated that miR-1 could inhibit cell proliferation, clonogenicity, cell invasion and motility.Bioinformatics analyses identified the major biological processes that are targeted by miR-1.These results suggest that miR-1 has a tumour-suppressive effect on the development and progression of ESCC.The findings of this study contribute to current understanding of the functions ofmiR-1 in ESCC.