Studying on relation between peritoneal function by Peritoneal Equilibration Test (PET) and some clinical and resume biochemical features of 261 chronic renal failure patients treating with Continuous Ambulatory Peritoneal Dialysis, the results show that D4/P creatinin of diabetic patients is higher than that of non-diabetic ones (0.74 + or - 0.09 versus 0.695 + or - 0.08), p 0.001. There is negative correlation between D4/P creatinin and during of peritoneal dialysis, r