To investigate the relationship between adenine-induced serum Bcl-3, Gal-3, TGF-β1 and renal interstitial fibrosis in rats with chronic kidney disease. Methods Twenty rats were randomly divided into normal control group (n=10) and model group (CKD group, n=10), and the model group was given adenine gavage and the control group was given equal volume of saline gavage, and the rats were executed at the 3rd and 6th weeks, respectively. Blood was collected to detect urea nitrogen, creatinine and Bcl-3, Gal-3, TGF-β1 levels. HE staining was used to observe renal pathological changes. Masson staining was used to observe interstitial fibrosis and its severity. Immunohistochemical staining was used to observe the expression of α-SMA protein in renal tissues. Results Compared with the control group, the levels of blood urea nitrogen, creatinine, Bcl-3, Gal-3 and TGF-β1 were significantly increased in the CKD group at all time points (P＜0.05), and the pathological changes of renal tubular epithelial cell degeneration and necrosis and interstitial fibrosis were seen in the renal tissue of the CKD group by HE staining. The expression of α-SMA protein was also significantly increased (P＜0.05). Correlation analysis showed a positive correlation between blood Bcl-3, Gal-3, and TGF-β1 levels and the relative area of renal interstitial fibrosis (rs=0.776, P＜0.001; rs=0.58, P＜0.001; rs=0.52, P=0.001). Conclusion Serum Bcl-3, Gal-3 and TGF-β1 levels were significantly increased in adenine-induced CKD model rats and were closely correlated with the severity of renal fibrosis, which is expected to be a novel biomarker for assessing renal fibrosis