Abstract: Objective: To investigate the expression levels of circ_0061140 and miR-548b-3p in gastric cancer cells,and explore the effects of circ_0061140 on the proliferation,cycle distribution and apoptosis of gastric cancer cells by targeting miR-548b-3p. Methods: The relative levels of circ_0061140 and miR-548b-3p in human gastric mucosal cells GES1 and gastric cancer cell lines(SNU-1,AGS,HS-746T) were detected using the RT-qPCR.The small interfering RNA of circ_0061140,miR-548b-3p mimic,and small interfering RNA of circ_0061140 + miR-548b-3p inhibitor were transfected into SNU-1 cells,respectively.The viability of SNU-1 cells was detected by CCK-8 assay,the apoptosis and cycle distribution were detected by flow cytometry.The dual luciferase reporter experiment,RIP assay and RT-qPCR were used to analyze the target regulation relationship between circ_0061140 and miR-548b-3p. Results: Compared with GES1 cells,the relative level of circ_0061140 in SNU-1,AGS and HS-746T cells significantly increased(P<0.05),and the relative level of miR-548b-3p significantly decreased(P<0.05 to P<0.01).After interfering the expression of circ_0061140,the cell viability and S phase ratio of SNU-1 cells were significantly reduced(P<0.05 to P<0.01),and the apoptosis rate,G0/G1 phase ratio,and relative levels of miR-548b-3p significantly increased(P<0.05 to P<0.01).After overexpression of miR-548b-3p,the cell viability and S phase ratio of SNU-1 cells were significantly reduced(P<0.01),and the apoptosis rate and G0/G1 phase ratio significantly increased(P<0.01).The relative level of miR-548b-3p in SNU-1 cells was significantly reduced after overexpression of circ_0061140(P<0.05).The circ_0061140 was directly and specifically bound to miR-548b-3p.Inhibiting the miR-548b-3p expression could significantly reduce the effects of interfering circ_0061140 on the cell viability,cycle distribution and apoptosis of SNU-1 cells(P<0.01). Conclusions: The circ_0061140 expression is up-regulated,and the miR-548b-3p expression is down-regulated in gastric cancer cells.Interfering circ_0061140 can suppress the cell proliferation of gastric cancer cells by up-regulating miR-548b-3p,induce cell arrest in G0/G1 phase,and promote apoptos.