Background: Gastric cancer (GC) is the most common cancer in the world. Despite the advancement of the treatment of GC, the 5-year overall survival rate is still very low. MicroRNAs (miRNAs) play important roles in the pathogenesis of GC. A recent study suggested that miR-363-3p plays a role in the development of GC. However, the function of miR-363-3p in GC is not fully understood. Material/Methods: The network of NOTCH1 and the involved molecules was constructed by use of Cytoscape software. MiR-363-3p levels in GC tissues and cells were tested by qRT-PCR. Cells were miR-363-3p mimics or anti-miR-363-3p transfected by Lipofectamine. Bioinformatics algorithms from TargetScanHuman were used to predict the target genes of miR-363-3p. The NOTCH1 protein level was tested by Western blot. The interaction between miR-363-3p and NOTCH1 was confirmed by dual luciferase assays. Results: MiR-363-3p showed low levels in GC tissues and cells. Enforced expression of miR-363-3p inhibited cell growth and migration of GC cells and vice versa. NOTCH1 is the targeted gene of miR-363-3p. Conclusions: MiR-363-3p plays a tumor suppressor role in GC.