Abstract: Objective To assess the physical function and comorbidity burden of elderly patients with chronic kidney disease (CKD)and compare the difference between each stage. Methods The participants were military elderly patients with CKD hospitalized in the department of geriatric nephrology of our hospital from January 1, 2016 to December 31, 2017. Based on the estimate glomerular filtration rate (eGFR), they were divided into stage 3a, 3b, 4, and 5 groups. The Barthel index and modified cumulative illness rating scale-geriatric (MCIRS-G) were used to evaluate the patients’ physical function and the comorbidity burden in order to compare the difference of each stage and analyze the correlation of different characteristics. Results A total of 84 male elderly patients with CKD were recruited in the study, with mean age of (85.12±8.99) years. The physical function of patients in stage 4 was worse than that of stage 3a and 5 (55.00±28.72 vs 77.50±23.66 and 78.00±22.01, P< 0.05 respectively). The albumin of patients in stage 4 was lower than that of stage 3a and stage 5 (35.45±4.50) g/L vs (39.18±2.76) g/L and (39.32±3.04) g/L, P< 0.05 respectively.The MCIRS-G score of stage 3a was lower than that of stage 4 (26.25±3.17 vs 28.82±1.94, P< 0.05). The incidence of diabetes increased with the progression of CKD (P< 0.05). In the correlation analysis, the score of MCIRS-G had negative correlation with the score of Barthel Index (r=-0.636, P< 0.05), while albumin had positive correlation with the score of Barthel Index (r=0.400, P< 0.05). Conclusion For elderly population, CKD is associated with physical function decline and comorbidity burden. The stage 4 is the high risky period of physical function decline and being stricken with comorbidity burden.