Objective To investigate the expression of circular RNA circSP3 (hsa-circ-0002642) in hepatocellular carcinoma (HCC) and its effect on proliferation and migration of HCC cells. Methods The tumor tissue and the adjacent paratumor tissue samples were collected from 42 HCC patients who underwent surgery from Jun. 2017 to Dec. 2018 in Department of Hepatobiliary Surgery, the First Affiliated Hospital of Chongqing Medical University. The expression of circSP3 in the samples was detected by real-time quantitative PCR, and the relationship between circSP3 expression in the tumor tissues and clinicopathological parameters of the patients was analyzed. Human HCC cell lines (Hep-3B, Huh7, SMMC-7721 and Bel-7402) and human normal liver cell line (HL-7702) culturion, and the expression of circSP3 was detected. After circSP3 overexpression and interference plasmids transfection into Hep-3B and Huh7 cells, the cell proliferation was detected by cell counting kit-8 (CCK-8) method, the invasion and migration abilities were detected by Transwell assay, and expression levels of epithelial-mesenchymal transformation (EMT)-associated markers (vimentin and E-cadherin) were determined by Western blotting. Results The expression of circSP3 of tumor tissues was significantly higher than that of the paratumor tissues in the HCC patients (P<0.01), and the expression of circSP3 was positively correlated with the tumor maximum diameter and clinical TNM stage (both P<0.05). The expression levels of circSP3 in the 4 HCC cell lines were significantly higher than that in the normal liver cell lines (all P<0.01). Overexpression of circSP3 could significantly promote proliferation, invasion and migration of HCC cells (P<0.05, P<0.01), while interference circSP3 expression could significantly inhibit the proliferation, invasion and migration (P<0.05, P<0.01). The expression of vimentin was significantly higher in circSP3-overexpressed cells than that in control cells (P<0.05), while it was significantly lower in circSP3-interfered cells than that in control cells (P<0.05). The expression of E-cadherin was significantly lower in circSP3-overexpressed cells than that in control cells (P<0.01), while it was significantly higher in circSP3-interfered cells than that in control cells (P<0.01). Conclusion The abnormal expression of circSP3 is positively correlated with tumor size and TNM stage of HCC, and determining its expression is helpful to evaluate the severity and prognosis of HCC. CircSP3 can promote the proliferation of HCC cells, and may promote the migration and invasion by promoting the EMT process.