Objectives To evaluate the prevalence of insufficiency and deficiency of 25-hydroxyvitamin D3 [25 (OH) D3] in patients with chronic kidney diseases (CKD) at stage 5,and to analyze its influencing factors.Methods General data and laboratory test results of 96 inpatients with stage 5 CKD were analyzed retrospectively.Levels of 25 (OH) D3,white blood cell (WBC),hemoglobin (Hb),urea nitrogen (BUN),serum creatinine (Scr),carbon dioxide combining power (CO2 CP),albumin (Alb),alkaline phosphatase (ALP),total cholesterol (TCH),high density lipoprotein (HDL-C),low density lipoprotein (LDL-C),triglycerides (TG),calcium (Ca),phosphorus (P)and intact parathyroid hormone (iPTH) in palasma wewe collected.Correlation between 25 (OH) D3 and other parameters were analyzed.Results The average level of 25 (OH) D3 in total 96 patients with stage 5 CKD was 33.25(24.85,44.30) nmol/L,which was significantly lower than normal level (P ＜ 0.01).These patients were divided into three groups:patients without dialysis,patients with maintained hemodialysis(HD) and patients with maintained peritoneal dialysis(PD).The 25(OH) D3 levels of patients in those three groups were 32.70 (25.30,43.70) nmol/L,37.00 (29.20,48.65)nmol/L and 27.05 (19.20,35.37) nmol/L respectively.The prevalence of 25 (OH) D3 insufficiency of all patients was 32.29％,and in the three groups were 27.91％,45.45％ and 20％ respectively.The prevalence of deficiency 25(OH) D3 of all was 64.58％,and in the three groups were 67.44％,51.52％ and 80％ respectively.The prevalence of decreased 25(OH) D3 level of all the patients was 96.88％,and that of the three groups were 95.35％,96.97％ and 100％.Single factor correlation analysis demonstrated that the 25 (OH) D3 level was correlated with Hb level (r =0.222),Alb level (r =0.398) (P ＜ 0.05).Multiple linear regression analysis showed that Alb level was positively correlated with 25 (OH) D3.Conclusions The prevalence of insufficiency and deficiency of 25 (OH) D3 in patients with stage 5 CKD is quite high.Alb is the independent risk factor for 25 (OH) D3 level in patients with stage 5 CKD.