Abstract: Objective To explore the changes of renal artery resistance index(RRI) in patients with chronic kidney disease(CKD) at different stages and examine its correlation with early renal function damage. Methods From January 2016 to September 2020, clinical data of 611 CKD patients were collected as case group. Estimated glomerular filtration rate(eGFR) was calculated by CKD-EPIscr equation. The case group was further divided into 5 groups according to CKD stage. Meanwhile 100 healthy volunteers in the same period were chosen as control group. RRI, serum β2-microglobulin(β2-MG), serum cystatin C(CysC), serum creatinine(Scr) and serum urea nitrogen(BUN) were measured. The differences between case and control groups were compared by one-way ANOVA;the abnormal detection rate of each group was calculated;the diagnostic efficiency of the above indicators in CKD patients was analyzed by receiver operating characteristic(ROC) curve. Results The mean values of RRI, β2-MG, CysC, Scr and BUN were higher in each case group than those in control group(P<0. 05). In stages 1 and 2, the abnormal detection rate of β2-MG, CysC and RRI was higher than that of any single detection index, followed by the abnormal detection rate of RRI. Receiver operating characteristic(ROC) curve showed that area under the curve(AUC) and Youden index of RRI were the largest in single detection indexand AUC and Youden index of combined detection of β2-MG, CysC and RRI were the largest. Conclusion RRI, β2-MG and CysC may be utilized as sensitive detection parameters of early renal damage in CKD, especially RRI. Combined detection of β2-MG, CysC and RRI can improve abnormal detection rate and boost diagnostic efficiency. Thus it provides clinical references for early diagnosis and treatment of CKD.