Objective: To investigate the regulatory effect of miR-193b on urokinase-type plasminogen activator (uPA), which was selected according to target gene predictions, in stomach cancer cells and the mechanism. Methods: Gastric cancer BGC823 cells were transiently transfected with the miR-193b sense sequence (sense sequence transfection group), miR-193b antisense sequence (antisense sequence transfection group) and scrambled sequence (negative transfection group) respectively, with the untransfected BGC823 cells as a blank control. In each group of cells, the expression levels of miR-193b were detected by real-time PCR, and the mRNA and protein expressions were determined by RT-PCR and Western blot analysis, respectively. Results: Compared with blank control group, the miR-193b expression in negative transfection group had no obvious change (P>0.05), while it was significantly increased in sense sequence transfection group and significantly decreased in antisense sequence transfection group (both P<0.05); the uPA mRNA expression levels in all transfection groups had no obvious change; the uPA protein expression in negative transfection group showed no apparent change, but it was reduced in sense sequence transfection group and increased in antisense sequence transfection group. Conclusion: uPA may be the target gene of miR-193b; miR-193b may negatively regulate its expression through inhibition of its post-transcriptional translation, and thereby enhance the invasiveness of gastric cancer cells.