Our study showed that miR-30b expression was inversely correlated with PAI-1 expression in gastric cancer cell lines and tumor tissues, PAI-1 overexpression could counteract the effect of promoting apoptosis by miR-30b, and ectopic expression of miR-30b had similar promoting-apoptosis effect compared with silencing PAI-1 expression. The gene discussed is SERPINE1; the disease is neoplasm.