In this study, we demonstrated that miR-34b overexpression significantly decreased the protein expression levels of c-MYC, PCNA and Cyclin D1 in Caco-2 cells, indicating that Wnt/β-Catenin is a key downstream signaling pathway in response to the regulation of miR-34b in colon cancer cells. This evidence concerns the gene PCNA and malignant colon neoplasm.