Abstract: Objective To investigate the role of microRNA-145-5p (miR-145-5p) in regulating the proliferation, migration, invasion and apoptosis of human endometrial carcinoma cells. Methods Human endometrial carcinoma Ishikawa cells were transfected with miR-145-5p mimic, miR-145-5p inhibitor, or their negative controls via liposome (Lipo2000), and the changes in the expression of miR-145-5p was verified by real-time PCR. The effects of overexpression or inhibition of miR-145-5p on the proliferation, migration, invasion and apoptosis of the cells were evaluated using MTT assay, wound healing assay, Transwell assay or flow cytometry. Bioinformatic analysis was performed to predict the target genes of miR-145-5p. The mRNA and protein expression levels of the downstream target of miR-145-5p, namely dual specific phosphatase 6 (DUSP6), were detected using real-time PCR and Western blotting. Results Transfection of the cells with miR-145-5p mimic significantly suppressed the proliferation of Ishikawa cells, while transfection with miR-145-5p inhibitor obvious enhanced the proliferation of the cells (P<0.05). Over-expression of miR-145-5p significantly suppressed the migration and invasion and promoted apoptosis of the cells, and inhibition of miR-145-5p caused the reverse changes (P<0.05). Bioinformatic analysis showed that DUSP6 was the potential target gene of miR-145-5p. Over-expression of miR-145-5p significantly lowered while inhibition of miR-145-5p significantly enhanced the expression of DUSP6 protein (P<0.05). Conclusion Overexpression of miR-145-5p inhibits the proliferation, migration and invasion and promotes apoptosis of endometrial cancer cells possibly by negative regulation of DUSP6 expression.