ObjectiveTo investigate the value of serum protoporphyrin IX (PPIX) measurement in evaluating liver damage in patients with HBV-related chronic liver diseases. MethodsA total of 110 patients who were diagnosed with HBV-related chronic liver diseases in The First Affiliated Hospital of Xi’an Medical University from October 2018 to October 2019 were enrolled as case group ［chronic hepatitis B (CHB) group with 50 patients, liver cirrhosis (LC) group with 40 patients, and hepatocellular carcinoma (HCC) group with 20 patients］, and 40 healthy individuals were enrolled as control group. High-performance liquid chromatography was used to measure serum PPIX. A one-way analysis of variance was used for comparison of normally distributed continuous data between groups, and the Mann-Whitney U test or the Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between groups; the chi-square test was used for comparison of categorical data between groups; the receiver operating characteristic (ROC) curve was plotted to analyze diagnostic value; a Spearman correlation analysis was also performed to investigate correlation. ResultsThe CHB, HC, and HCC groups had a significantly higher level of PPIX than the control group ［44.29 (25.99-85.36) ng/dl, 72.73 (48.28-90.43) ng/dl, and 91.79 (68.34-121.52) ng/dl vs 15.43 (10.87-20.16) ng/dl, all P＜0.05］, and the patients with decompensated LC had a significant increase in the level of PPIX compared with those with compensated LC ［54.50(29.14~85.65) vs 76.09(53.47~104.37)，Z=-2.176, P＜0.05］. PPIX had a sensitivity of ＞85% and a specificity of ＞60% in the diagnosis of CHB, LC, and HCC. The patients in the latent stage of CHB had a significantly higher level of PPIX than those in the control group (Z=-4.303, P＜0.05). In the patients with LC, PPIX was moderately positively correlated with total bilirubin (TBil) (rs=0.587, P＜0.05) and moderately negatively correlated with albumin (rs=-0.408, P＜0.05); in the patients with HCC, PPIX was moderately positively correlated with TBil (rs=0.470, P＜0.05) and moderately negatively correlated with cholinesterase (rs=-0.459, P＜0.05). ConclusionElevated serum PPIX is an early event of liver damage in patients with HBV-related chronic liver diseases and can thus be used as a sensitive parameter for the early warning and assessment of liver damage.