This study was designed to explore the effects of curcumin on proliferation, migration and invasion of human lung adenocarcinoma LTEP-A2 cells and determine its mechanism. Human lung adenocarcinoma LTEP-A2 cell was cultured in vitro. After incubation with different concentrations of curcumin (5, 10, 15 μmol/L), the effects of curcumin on proliferation, migration and invasion of human lung adenocarcinoma LTEP-A2 cells were observed by MTT assay, wound healing and transwell assay. The expression levels of COX-2 and MMP-9 were detected by western blot. Compared with the blank control group, curcumin decreased the survival rate of LTEP-A2 cells, shorten the cell migration distance and decrease the number of LTEP-A2 cells penetrating membrane. The expression levels of COX-2 and MMP-9 were both down-regulated by curcumin. Curcumin can inhibit the proliferation, migration and invasion of human lung adenocarcinoma LTEP-A2 cells. The mechanism may be related to the down-regulation of COX-2 and MMP-9 expression.