Objective To investigate the clinical significance of autophagy-related protein 7 (ATG7) in the diagnosis of HBV-related hepatocellular carcinoma (HBV-HCC) by measuring the expression level of serum ATG7 in patients with HBV-HCC. Methods A total of 50 patients with chronic hepatitis B (CHB) and 89 patients with HCC who were hospitalized in Mengchao Hepatobiliary Hospital of Fujian Medical University from June 2018 to December 2020 were enrolled, among whom 67 patients had HBV-HCC (HBV-HCC group) and 22 patients had no HBV-HCC (non-HBV-HCC group), and 20 healthy volunteers who underwent physical examination were enrolled as healthy control (HC) group. Demographic data and laboratory data including alpha-fetoprotein (AFP) were collected from each group, and ELISA was used to measure the serum level of ATG7. The receiver operating curve (ROC) was plotted for ATG7 and AFP used alone or in combination, and the area under the ROC curve (AUC) was compared. The Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between multiple groups, and the Mann-Whitney U test was used for comparison between two groups; the chi-square test was used for comparison of categorical data between groups; a Spearman correlation analysis was used to investigate correlation. Results The serum level of ATG7 was 22.88(19.79-23.04) ng/mL in the HBV-HCC group, 17.06(14.45-19.40) ng/mL in the non-HBV-HCC group, 19.21(16.65-20.82) ng/mL in the CHB group, and 13.82(8.70-17.82) ng/mL in the HC group, with a significant difference between groups ( χ 2 =65.144, P < 0.001). ATG7 had an AUC of 0.818 (95% confidence interval [ CI ]: 0.743-0.879) and AFP had an AUC of 0.777 (95% CI : 0.698-0.843) in the diagnosis of HBV-HCC, suggesting that ATG7 had a slightly higher AUC than AFP ( Z =0.852, P =0.394). ATG7 combined with AFP had an AUC of 0.859 (95% CI : 0.790-0.913) in the diagnosis of HBV-HCC, which was significantly higher than the AUC of ATG7 alone ( Z =2.192, P =0.028) and AFP alone ( Z =2.076, P =0.038). Conclusion ATG7 is a good marker for the diagnosis of HBV-HCC, and combined measurement of ATG7 and AFP can significantly improve the diagnostic rate for HBV-HCC.