Objective. We investigate whether low-protein diet would show benefits in suppressing peritoneal transport rate in peritoneal dialysis (PD) patients. Methods. This is a supplemented analysis of our previously published trial, which randomized 60 PD patients to receive low- (LP: dietary protein intake of 0.6–0.8 g/kg/d), keto-acid-supplemented low- (sLP: 0.6–0.8 g/kg/d with 0.12 g/kg/d of keto acids), or high- (HP: 1.0–1.2 g/kg/d) protein diet and lasted for one year. In this study, the variations of peritoneal transport rate were assessed. Results. While baseline D/P cr (dialysate-to-plasma concentration ratio for creatinine at 4 hour) and D/D0 glu (dialysate glucose at 4 hour to baseline dialysate glucose concentration ratio) were similar, D/P cr in group sLP was lower, and D/D0 glu was higher than those in the other two groups ( ) at 12th month. D/D0 glu increased ( ), and D/P cr tended to decrease, in group sLP. Conclusions. Low-protein diet with keto acids may benefit PD patients by maintaining peritoneum at a lower transport rate.