Objective:To explore the mechanism of circ_0014130/miR-671-5p/PDL1 axis in the progression of gastric cancer.Methods:In order to explore the role of circ_0014130 and miR-671-5p in gastric cancer cells,AGS and HGC27 cells were divided into si-NC group,si-circ_0014130 group,si-circ_0014130+inhibitor NC group and si-circ_0014130+miR-671-5p inhibitor group.In order to explore the role of miR-671-5p and PDL1 in gastric cancer cells,AGS and HGC27 cells were divided into mimic NC group,miR-671-5p mimic group,miR-671-5p mimic+pcDNA-NC group,and miR-671-5p mimic+pcDNA-PDL1 group.The targeting binding relation-ship between circ_0014130 and miR-671-5p,miR-671-5p and PDL1 were analyzed by Dual luciferase reporter gene assay.The cell via-bility was detected by CCK-8 assay,cell proliferation was detected by EdU assay,cell apoptosis was detected by flow cytometry,and cell invasion was detected by Transwell assay.The RNA expression level was detected by RT-qPCR,and protein expression level of PCNA,Bcl-2,Bax and PDL1 were detected by western blot.Results:There was a binding site between circ_0014130 and miR-671-5p,and the expression of circ_0014130 was increased in AGS and HGC27 cells(P＜0.05).The knockdown of circ_0014130 expression inhibited cell proliferation and invasion,promoted cell apoptosis.The down-regulation of miR-671-5p counteracted the inhibitory effect of circ_0014130 knockout on the malignant biological behavior of gastric cancer cells.There was a binding site between miR-671-5p and PDL1,and overexpression of miR-671-5p inhibited cell proliferation and invasion,promoted cell apoptosis.The overexpression of PDL1 partially offset the inhibitory effect of miR-671-5p on the malignant biological behavior of gastric cancer cells.Conclusion:circ_0014130 may promote the proliferation and invasion of gastric cancer cells and inhibit the apoptosis of gastric cancer cells by regulating miR-671-5p/PDL1 axis.