Objective  To investigate the association between serum chitinase-3-like protein 1 (CHI3L1) level and risk of arteriovenous fistula (AVF) occlusion in patients undergoing maintenance hemodialysis (MHD).  Method  A total of 168 patients undergoing MHD at the Huili People's Hospital between January 2023 and March 2024 were enrolled for this study. According to the occurrence of  AVF occlusion in a year, the patients were divided into the occlusion group (n=33) and the control group (n=135). Baseline clinical data and serum CHI3L1 level were collected from both groups. Logistic regression analysis was performed to investigate the correlation between serum CHI3L1 level and AVF occlusion in the MHD patients.  Results  There were statistically significant differences in primary disease (χ²=6.390, P=0.041), serum albumin (t=2.133, P=0.037), serum calcium (t=2.703, P=0.010), calcium-phosphorus product (t=2.124, P=0.040) and serum CHI3L1 level (t=2.754, P=0.008) between the occlusion group and the control group. Multivariate logistic regression analysis revealed that higher serum albumin (OR=0.816, 95% CI:0.719～0.926, P=0.002) was the protective factor against the risk of AVF occlusion (P<0.05), while higher serum calcium (OR=1.641, 95% CI:1.005～2.682, P=0.048), high calcium-phosphorus product (OR=1.053, 95% CI:1.010～1.099, P=0.015) and high serum CHI3L1 level (OR=1.135, 95% CI:1.077～1.195, P=0.000) were the independent risk factors for AVF occlusion in MHD patients. ROC curve analysis showed that the area under the curve (AUC) of baseline serum CHI3L1 level for predicting AVF occlusion in MHD patients was 0.724, with a sensitivity of 62.96%, a specificity of 93.94% and a cut-off serum CHI3L1 level of 123.13 ng/mL; the AUC of combined prediction model was 0.811, with a sensitivity of 76.30% and a specificity of 75.76%.  Conclusion  Elevated baseline CHI3L1 level is independently associated with the higher risk of AVF occlusion, and can be used for predicting AVF occlusion. Additionally, the combined use of serum albumin, serum calcium, and calcium-phosphorus product yields a higher predictive value for AVF occlusion in MHD patients.