Background: Studies have shown that curcumin can regulate the expressions of a variety of miRNAs and affect tumor cell biological behavior. However, whether curcumin affects the biological behavior of gastric cancer cells by regulating expression of miR-539 has not been clarified. Aims: To investigate the effect and mechanism of curcumin on proliferation, migration, invasion, apoptosis of gastric cancer cells by regulating the expression of miR-539. Methods: A total of 49 gastric cancer tissue specimens were collected. Gastric cancer AGS, SGC7901 cells were divided into blank group, curcumin group, negative control group, miR-539 mimics group, miR-539 inhibitor group, inhibitor control group, miR-539 inhibitor +curcumin group. qRT-PCR was used to detect the mRNA expression of miR-539 in gastric cancer tissue and cells. Cell proliferation was detected by MTT. Scratch test, Transwell test were used to detected cell migration and invasion. Cell apoptosis was determined by flow cytometry. Western blotting was used to detect protein expressions of APOBEC3B, c-Myc, cyclin D1, claudin-1 and N-cadherin. Results: Expressions of miR-539 mRNA in gastric cancer tissue and gastric cancer cells were significantly decreased than those in corresponding controls (P<0.05), and was related to tumor stage in gastric cancer patients (P<0.05). Curcumin up-regulated the expression of miR-539 mRNA in a dose-dependent manner (P<0.05). Compared with corresponding control group, cell proliferation, migration and invasion were significantly decreased in miR-539 mimics group and curcumin group (P<0.05), cell apoptosis rate was significantly increased (P<0.05), and protein expressions of APOBEC3B, c-Myc, cyclin D1, claudin-1 and N-cadherin were significantly decreased (P<0.05). Conclusions: Expression of miR-539 is decreased in gastric cancer, and curcumin can inhibit proliferation, migration and invasion of gastric cancer cells and induce cell apoptosis by up-regulating the expression of miR-539.