Objective To investigate the role and mechanism of circular RNA containing pleckstrin homology do-main of Pleckstrin homology domain family M member 3(circRNA_PLEKHM3)in regulating epithelial-mesenchy-mal transition(EMT)behavior in cervical cancer cells through the miR-320 and KLF4.Methods The expression levels of circRNA_PLEKHM3 in cervical cancer cells Hela and CaSki were detected by real-time quantitative PCR(qRT-PCR).RNA fluorescence in situ hybridization was used to determine the localization of circRNA_PLEKHM3 in human cervical cancer epithelial cells CaSki.Dual luciferase reporter gene experiments were conducted to inves-tigate the targeting relationship between circRNA_PLEKHM3 and miR-320,as well as the targeting relationship be-tween miR-320 and KLF4.CaSki cells were overexpressed with circRNA_PLEKHM3.Additionally,three groups were set up:overexpression of miR-320 on the basis of circRNA_PLEKHM3 overexpression,silencing of KLF4 on the basis of circRNA_PLEKHM3 overexpression,and silencing of KLF4 on the basis of miR-320 overexpression.qRT-PCR was performed to detect the expression levels of miR-320 in CaSki.Western blot experiments were con-ducted to determine the expression of KLF4 and EMT markers including E-cadherin,N-cadherin,Vimentin,MMP-2,and MMP-9 in CaSki cells.Transwell assays were performed to measure cell migration and invasion.Results The expression of circRNA_PLEKHM3 decreased in Hela and CaSki cells(P<0.05),mainly localized in the cy-toplasm.The dual luciferase reporter gene experiment demonstrated a targeting relationship between miR-320 and circRNA_PLEKHM3,as well as between KLF4 and miR-320.Overexpression of circRNA_PLEKHM3 inhibited the protein expression of miR-320,N-cadherin,Vimentin,MMP-2,and MMP-9,up-regulated the protein expression of E-cadherin,and reduced cell migration and invasion(P<0.05).Overexpression of miR-320 or silencing of KLF4 on the basis of circRNA_PLEKHM3 overexpression both promoted the protein expression of miR-320,N-cad-herin,Vimentin,MMP-2,and MMP-9,down-regulated the protein expression of E-cadherin,and increased cell migration and invasion(P<0.05).However,silencing of KLF4 on the basis of miR-320 overexpression inhibited the protein expression of KLF4,N-cadherin,Vimentin,MMP-2,and MMP-9,up-regulated the protein expression of E-cadherin,and reduced cell migration and invasion(P<0.05).Conclusion Overexpression of circRNA_PLEKHM3 regulates EMT in cervical cancer cells through the miR-320/KLF4 axis.