【Abstract】 Objective To explore and analyze the relationship between the serum fibroblast growth factor 23 (FGF23) and Klotho protein levels and the calcium and phosphorus metabolism, atherosclerosis and left ventricular hypertrophy in maintenance hemodialysis (HD) and peritoneal dialysis (PD) patients.Methods Fifty HD patients and fifty PD patients treated in the department of blood purification, Zhongshan Hospital Affiliated to Dalian University from January 2015 to April 2016 were selected as the HD group and the PD group respectively. Another thirty healthy people who received physical examination in our hospital in the same period were selected as the control group. The effects of different dialysis methods on FGF23 and Klotho protein levels were compared through collating data, laboratory testing and ultrasonography, and the relationship between the FGF23 and Klotho protein levels and the phosphorus metabolism, arteriosclerosis and left ventricular hypertrophy was analyzed. Results The FGF23 level in the HD and PD groups was significantly higher than that in the control group, and the FGF23 level in the HD group was significantly higher than that in the PD group, and the difference was statistically significant (P＜005). The Klotho protein level in the HD and PD groups was significantly lower than that in the control group, and the difference was statistically significant (P＜005). The Klotho protein level in the HD group was similar with that in the PD group, and the difference was not statistically significant (P＞ 005). FGF23 level was positively correlated with calcium and phosphorus metabolism (r=05323, 05178, 05178, P＜005), was positively correlated with secondary hyperparathyroidism (r=03038, P＜005), and was positively correlated with carotid atherosclerosis (R=02987, P＜005); Klotho protein level was negatively correlated with calcium and phosphorus metabolism (r=05103,01105,05264, P＜005), and was positively correlated with secondary hyperparathyroidism (r= 03254, P＜005). Conclusions There is a high expression of FGF23 and low expression of Klotho protein in patients with endstage renal disease (ESRD) dialysis, which are closely related to hyperphosphatemia, secondary hyperparathyroidism and atherosclerosis in HD and PD patients.