Background Gastric cancer (GC) is one of the most common tumors and the molecular mechanism underlying its metastasis is still largely unclear.Methods the miR-25 expression in primary tumors tissues and plasma of patients with GC was measured via quantitative Reversetranscriptase Polymerase Chain Reaction (qRT-PCR).The proliferation, migration and invasion of GC cells were analyzed in vitro, and the ability of cell migration and invasion was assessed via a nude mice model.Microarray was used to screen the candidate target genes of miR-25.The receiver operating characteristics (ROC) was used to analyze the sensitivity and specificity of cutoff value of miR-25 in distinguishing the GC patients with death from those with survival.