〔Abstract〕 Objective To evaluate the differences of serum total light chain(sTLC), urine total light chain(uTLC) and serum free light chain(sFLC) in different stages of chronic kidney disease(CKD) and their correlation with renal function indexes. To investigate the predictive value of light chain indexes in CKD staging. Methods 292 patients with CKD were analyzed retrospectively, and plasma cell diseases, acute kidney injury and tumor diseases were excluded. According to the estimated glomerular filtration rate(eGFR), CKD patients were divided into five groups from CKD 1 stage to CKD 5 stage. The levels of sTLC, uTLC, sFLC and corresponding biochemical indexes of CKD patients were detected, and the differences and correlations among the indexes of each group were compared. The receiver operating curve(ROC curve) was used to analyze the predictive value of each light chain index in CKD stage, with CKD1-2 stage combined as control group and CKD3-5 stage combined as case group. Results There was no significant difference in sTLC κ, sTLC λ, sTLC κ/λ and sFLC κ/λ among CKD1-5 stage(P>0.05). There were significant differences between sFLC κ, sFLC λ and uTLC κ, uTLC λ among CKD1-5 stage(P<0.05), which increased with the increase of CKD staging. The correlation between sFLC κ, sFLC λ and serum creatinine(Scr), blood urea nitrogen(BUN), eGFR were better than uTLC κ, uTLC λ(P<0.001). The sTLC κ, sTLC λ, sTLC κ/λ and sFLC κ/λ had no correlation with renal function indexes(P>0.05). The best critical points of sFLC κ and sFLC λ for predicting CKD3-5 stage were 35.4 mg/L and 52.8 mg/L, and AUC was 0.916(0.883-0.949) and 0.915(0.881-0.949), which were higher than uTLC κ and uTLC λ,AUC was 0.811(0.754-0.869) and 0.787(0.728-0.846), respectively. Conclusion With the increase of CKD staging, the levels of sFLC and uTLC gradually increase. The sFLC and uTLC can effectively predict patients with CKD3 and above, which has an important reference value in stratified management of patients with CKD.