Objective To elucidate the prevalence of vitamin D insufficiency and deficiency in chronic kidney diseases (CKD) patients and provide the evidence for treatment of these patients. Methods Clinical data of 358 inpatients with CKD from stage 1 to stage 5 were analyzed retrospectively. Level of 25 (OH)D3 in these inpatients, as well as the levels of intact parathyroid hormone (iPTH), hemoglobin (Hb), serum creatinine (Scr), urea nitrogen (BUN), carbon dioxide combining power (CO2CP), alhumin (Alb), serum calcium (Ca) and blood serum (P) were examined. Correlation between 25 (OH)D3 and parameters was analyzed. Results The mean level of 25 (OH)D3 in these CKD patients was (18.58±11.7) μg/L, which was significantly lower than that of normal reference (P<0.01). The 25(OH )D3 levels of CKD patients from stage 1 to stage 5 were (25.84±9.71) μg/L, (20.76±6.99) μg/L, (20.40±17.02) μg/L, (19.49±11.29) μg/L, and (14.16±7.98) μg/L respectively. The prevalence of vitamin D defieiency was 39.66%, and from CKD stage 1 to stage 5 was 5.00%, 17.50%, 37.21%, 42.37% and 57.14%. The prevalence of vitamin D insufficiency was 44.97%, and from CKD stage 1 to stage 5 was 72,50%, 47.50%, 45.35%, 33.90% and 40.60%. The prevalence of decreased vitamin D level was 84.63%, and from CKD stage 1 to stage 5 was 77.50%, 65.00%, 82.56%, 76.27% and 97.74%. Single factor correlation analysis showed 25 (OH)D3 was correlated with Hb, Alb, Scr, eGRF and iPTH. Regression analysis indicated that 25 (OH)D3 was negatively correlated with iPTH and Scr, and positively correlated with Alb. According to K/DOQI, percentage of CKD patients from stage 3 to stage 5 who were consistent with vitamin D treatment was 87.20%, 83.05% and 26.31% based on 25 (OH)3 and iPTH levels, but such percentage was 16.28%, 35.59% and 26.31% based on iPTH level only. Conclusions The prevalence of vitamin D insufficiency and deficiency in patients with CKD is quite high. Alia, iPTH and Scr are key factors influencing vitamin D level. Vitamin D level should be measured among CKD patients in order to carry out corresponding treatment.