Objective To explore the advantages of early daytime ambulatory peritoneal dialysis in treatment of end-stage renal disease. Methods Eighty-four cases of initial peritoneal dialysis patients were randomly divided into two groups. The patients in the DAPD group (40 cases) received daytime ambulatory peritoneal dialysis; those in the CAPD group (44 cases) received continuous ambulatory peritoneal dialysis. Both groups continued to receive conventional drug therapy, and followed up for 24 months. In all patients calcium, phosphorus and parathyroid hormone were monitored; and urine volume, peritoneal dialysis volume, dialysis efficacy and residual renal function were recorded every six months. Results In both groups, hypocalcemia and hyperphosphatemia were improved after peritoneal dialysis (P < 0.05). After 24 months, the blood phosphorus level of the DAPD group was lower than that of the CAPD group (P < 0.05). In the early period, the parathyroid hormone level of the CAPD group was lower than that of the DAPD group (P < 0.05), but the difference was not significant after 18 months (P > 0.05). The urine volume and residual renal function decreased gradually in both groups, and they were lower in the CAPD group than in the DAPD group after 12 months (P < 0.05). The residual renal Kt/V in the DAPD group was higher than that in the CAPD group 12 months later (P < 0.05). The volume of peritoneal dialysis fluid in the DAPD group was smaller than that in the CAPD group 12 months later (P < 0.05). Conclusions Early daytime ambulatory peritoneal dialysiscan improve the status of calcium-phosphate metabolism. Daytime ambulatory peritoneal dialysis can protect the residual renal function, maintain higher residual renal Kt/V, and use less peritoneal dialysis fluid.