Circular RNAs (circRNAs) are a class of non-coding RNAs that participate in various biological processes and disease pathogenesis. However, the role of circRNAs in chronic myeloid leukemia (CML) remains largely unknown. In this study, high-throughput sequencing was performed to explore the expression profile of circRNAs in CML patients for the first time, and a large number of differentially expressed circRNAs were identified. In addition, we constructed potential circRNA-miRNA interaction networks in CML, including a detailed hsa_circ_0080145-mediated competing endogenous RNA (ceRNA) regulatory network. Furthermore, functional experiments demonstrated that hsa_circ_0080145 knockdown significantly suppressed CML cell proliferation and hsa_circ_0080145 regulated CML cell proliferation by acting as an miR-29b sponge.