Abstract: Objective: To investigate the expression of urokinase-type plasminogen activator receptor (PLAUR) in gastric cancer cells and its effects on the proliferation,invasion,migration and epithelial mesenchymal transition (EMT) of gastric cancer BGC823 cells. Methods: It is divided into control group (not transfected with any fragment),si-NC group (transfected with blank fragment),and si-PLAUR group (transfected with siRNA PLAUR knockdown fragment).Western blotting was used to detect the difference of PLAUR expression in human gastric mucosal cells GES-1 and gastric cancer cells SGC7901,BGC823 and MGC803.The expression of PLAUR gene in BGC823 cells was knocked down by siRNA transfection technique,and the transfection efficiency was verified by qRT-PCR.Cell proliferation was detected by clonogenesis assay,cell invasion was detected by Transwell assay,and cell migration was detected by scratch healing assay.The expression changes of E-Cadherin,N-Cadherin and Vimentin during EMT process were detected by Western blotting. Results: The expression of PLAUR in cancer tissues was significantly increased(P<0.01),and the expression level of PLAUR in gastric cancer was correlated with patient age,tumor diameter,and clinical stage(P<0.05).Compared with GES-1 cells,PLAUR expression in SGC7901,BGC823 and MGC803 cells was significantly increased (P<0.05).Compared with control group and si-NC group,the proliferation,invasion and migration ability of BGC823 cells in si-PLAUR group were significantly decreased (P<0.05).E-Cadherin protein expression increased in EMT signaling pathway,while N-Cadherin and Vimentin protein expression decreased (P<0.05). Conclusions: PLAUR expression is significantly increased in gastric cancer cells,and PLAUR expression in BGC823 cells inhibits cell proliferation,invasion and migration,and inhibits EMT process.