Objective：To study the effects of miR-629-5p on the biological behavior of gastric cancer cells and to identify its target gene. Methods：Quantitative real-time PCR（qRT-PCR） was used to detect the expression of miR-629-5p in 16 gastric cancer tis－sues and 3 gastric cancer cell lines. The cell experiment was divided into two groups：the experimental group（IN） and control group （NC）. Transfecting miR-629-5p inhibitor was used to down-regulate the miR-629-5p expression of MKN-45.CCK-8 assay and plate cloning assay was used to detect cell proliferation. Transwell chamber assay and wound healing assay was used to detect invasion and migration of MKN-45，and flow cytometry assay was used to detect apoptosis of MKN-45. MiRWalk2.0 was used to predict target genes of miR-629-5p，and Western blot was used to detect the expression of mitochondrial translational release factor 1 like（MTRF1L） in MKN-45. Results：The expression of miR-629-5p was significantly increased in gastric cancer tissues[2.081（0.231，7.216）] compared with that of paired normal gastric tissue[1.574（0.197，4.503）]（P=0.003）. The expression of miR-629-5p was sig－nificantly increased in gastric cancer cell lines（MKN-28：3.040±0.506；MKN-45：5.924±0.403；SCG-7901：3.377±0.372） compared with that of GES-1（1.017±0.226）（P=0.003）. After down-regulation of miR-629-5p expression，the proliferation of MKN-45 slowed down（IN：64±12；NC：102±12；P=0.018），the abilities of mi－gration（IN：106±9；NC：194±29；P=0.008） and invasion（IN：25±7；NC：60±9；P=0.007） decreased，and the number of apoptotic cells increased[IN：（19.257±2.440）%；NC：11.687±2.237；P=0.017]. There were 46 target genes predicted by miR-629-5p，one of which is MTRF1L. The down-regulation of miR-629-5p increased the expression of MTRF1L（IN：0.923±0.101；NC：0.556±0.026；P=0.004）. Conclusion：The expression of miR-629-5p is up-regulated in gastric cancer tissues and cell lines. miR-629-5p can promote the proliferation，enhance the migration and invasion abilities，and inhibit the apoptosis of MKN-45. MTRF1L may be one of miR-629-5 target genes.