This study will examine the peritoneal tissue, serum and dialysate proteins of continuous ambulatory peritoneal dialysis (CAPD) patients with different types of peritoneal solute transport by differential proteomics techniques. Correlation analysis will be used for the relationship between clinical data and the differential proteins, as well as verification of the differential proteins in the peritoneal tissue, serum and dialysate of patients with UFF. This study will be performed to identify the molecular difference between different types of peritoneal solute transport and explore biomarker for early detection as well as early intervention of peritoneal ultrafiltration failure.