ObjectiveTo observe whether proteinuria is relate to the decline of residual renal function (RRF) in peritoneal dialysis (PD) patients. MethodsThis is a prospective cohort study including 45 PD patients (underwent PD between January 2011 and January 2013) with a 12-month follow-up. All the patients were divided into 2 groups with respect to the initial proteinuria level: massive proteinuria group A (n=20) and non-massive proteinuria group B (n=25) at baseline. We established regression models to do univariate analysis and multivariate analysis of the relationship between the decline of RRF≥50% of baseline and the indices of age, sex, PD-associated peritonitis, baseliner residual glomerular filtration rate (rGFR), initial proteinuria, and use of ACEI/ARB. ResultsThe primary outcome (RRF>50% of baseline) at 12 months was 65% in group A, and 80% in group B (P<0.05). Based both on the results of univariate and multivariate Cox regression analysis, non-massive proteinuria and higher rGFR at baseline were factors to protect RRF from decline (P<0.05). ConclusionThe study demonstrates that massive proteinuria and lower rGFR at baseline may be associated with a rapid decline of RRF in PD patients. Treatment aimed at reducing albuminuria may lead to protect RRF and improve life quality of patients.