【Abstract】 Objective To explore arterial stiffness and its related factors in diabetic nephropathy patients treated with peritoneal dialysis (PD). Methods Serum albumin (ALB), C reactive protein (CRP), hemoglobin (Hb), triglycerides (TG), total cholesterol (TC), fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), intact PTH (iPTH), Ca+2, Kt/V, malondialdehyde (MDA), advanced oxidation protein products (AOPP), myeloperoxidase (MPO) and superoxide dismutase (SOD) levels were assayed, and intima-media thickness (IMT), pressure-strain elastic modulus (Ep) and stiffness index (SI) of carotid arteries were measured by ultrasound examination in 45 diabetic nephropathy patients and 53 non-diabetic nephropathy patients with PD. Results ALB, CRP ,Hb, FPG, HbA1c, Kt/V, MDA, AOPP, MPO, SOD, IMT, Ep and SI were significantly different between the two groups (P＜0.05). Multiple linear stepwise regression analysis revealed that EP and SI were influenced by the levels of HbA1c, MDA, AOPP, MPO and SOD. In diabetic nephropathy patients with PD, correlation analysis showed that IMT, Ep and SI were positively correlated with the levels of HbA1c, MDA, AOPP and MPO, and were negatively correlated with SOD level, while HbA1c was positively correlated with the levels of MDA, AOPP and MPO, and was negatively correlated with SOD level. Conclusion Arterial stiffness is worse in diabetic nephropathy patients with PD than in non-diabetic nephropathy patients with PD. HbA1c and oxidative stress closely relate to the arterial stiffness degree in diabetic nephropathy patients with PD.