Objective To explore the factors relating to sodium clearance in peritoneal dialysis patients. Methods A total of 156 maintenance peritoneal dialysis patients who had completed the modified peritoneal equilibrium test (PET) and dialysis adequacy test were enrolled in this study. Multifactor regression analysis was used for data analysis. Results This study firstly disclosed the influence factors relating to the peritoneal sodium removal, including infusion volume and ultrafiltration every day, sodium dip during modified PET, and sodium concentration difference between serum and fresh dialysate. The influence factors relating to total sodium clearance included ultrafiltration every day, urine volume every day, sodium dip during modified PET, and sodium concentration difference between serum and fresh dialysate. Multifactor regression analysis indicated the presence of significant relationships. Conclusions (1) Sufficient fluid removal is necessary for adequate sodium removal when traditional dialysate is used; (2) Low sodium dialysate may be useful for the relief of sodium retention; (3) Index of sodium clearance should be included in the evaluation of dialysis adequacy.