Abstract: Objective To investigate the expression of hsa_circ_0006156 in colorectal cancer (CRC) and its significance. Methods The expression of hsa_circ_0006156 in CRC tissues and adjacent normal tissues in 31 patients who underwent surgical treatment in our hospital from December 2014 to December 2015 was detected by real-time fluorescence-based quantitative PCR. The clinicopathological data were collected and analyzed to study its clinical significance. The interaction between hsa_circ_0006156 and microRNAs was predicted and analyzed by bioinformatic software such as Blast and Bedtools. Results Compared with the normal tissues, hsa_circ_0006156 was significantly down-regulated in cancer tissues with low expression in 24 patients (77.4%), while it was up-regulated in 7 patients (22.6%), and its expression was correlated with tumor size (P=0.042). ROC curve was constructed for differentiating CRC tissues from normal tissues. The AUC (area under curve) was up to 72.3% (95% CI: 0.592 - 0.853), and the sensitivity and specificity of hsa_circ_0006156 were 71% and 77.4%, respectively. hsa_circ_0006156 had binding sites of hsamiR-5011 (n=24), hsa-miR-4775 (n=22), hsa-miR-4445 (n=20), and hsa-miR-627 (n=12). Conclusion The expression of hsa_circ_0006156 is down-regulated in CRC and is a potential diagnostic biomarker for clinical diagnosis. hsa_circ_0006156 may act as miRNA sponge in post-transcriptional regulation.