The expression and roles of MicroRNA-381 (miR-381) has been explored in several types of human cancers. However, its biological functions in colon cancer remain largely unknown. Quantitative real-time PCR assays were used to detect the expression of miR-381 in human colon cancer tissues and adjacent normal tissues. miR-381 antisense oligos and mimics were introduced into SW480 and HCT116 cells. Bioinformatic prediction analysis was performed to identify the potential targets of miR-381. Protein expression analysis, luciferase assays and rescue assays were used to confirm the substrate of miR-381. We found that miR-381 was significantly down-regulated in human colon cancer tissues, compared with adjacent normal tissues. Introduction of miR-381 antisense oligos into SW480 and HCT116 cells promoted cell proliferation and invasion. Besides, inhibition of miR-381 could also support tumor growth in the nude mice. Additionally, bioinformatic prediction suggested that the nuclear receptor liver receptor homologue 1 (LRH-1) is a target gene of miR-381. Thus, our data suggested that down-regulation of miR-381 plays an important role in the colon cancer progression.