The present invention provides a means which can appropriately control the balance between water and sodium in peritoneal dialysis therapies while avoiding adverse effects on the residual renal function and without causing hyponatremia. This peritoneal dialysate fluid contains 1.5 to 1.8 w/v% of glucose and 120 to 130 mEq/L of sodium, and is used alone one or two times a day. The peritoneal dialysate fluid is used in combination with another peritoneal dialysate fluid containing 1.35 to 2.5 w/v% of glucose and 132 to 135 mEq/L of sodium in peritoneal dialysis where the following steps are performed three to five times a day: injecting 1.5 to 2.0 L of a peritoneal dialysate fluid into the abdominal cavity of a subject； retaining the peritoneal dialysate fluid； and discharging the peritoneal dialysate fluid.
