Ethnopharmacological relevance: Stage 3 is the key phase of chronic kidney disease. Traditional Chinese medicine (TCM) has been used for the treatment of chronic kidney disease. But a large sample trial is desirable. Materials and methods: A total of 578 Chinese patients with primary glomerulonephritis in CKD stage 3 were randomly assigned to three groups: patients received TCM (TCM group). benazepril (Ben group), TCM combined with benazepril (TCM + Ben group). Patients were followed up for 24 weeks. The primary endpoint was the time to the composite of 50% increased of serum creatinine, end stage renal disease or death. Results: eGFR in the TCM and the TCM + Ben group were improved (week 24 vs. baseline, P < 0.05) while eGFR in the Ben group was decreased (week 24 vs. baseline, P > 0.05). 24 h urinary protein excretion (UP) and urinary albumin/creatinine (UAlb/Cr) were decreased in the TCM + Ben (week 24 vs. baseline, P < 0.05) and the Ben group (week 24 vs. baseline. P> 0.05). UP and UAlb/Cr were increased in the TCM group to week 12, then were stable (week 24 vs. baseline, P < 0.05). The hemoglobin in the TCM group was also improved (week 24 vs. baseline, P < 0.05). The accumulative survival rate in the TCM + Ben group was higher than that in the TCM group and the Ben group (P = 0.044). Side effects in the TCM group were the lowest in these groups (P < 0.05). The patients with dry cough in the TCM + Ben group and the Ben group were increased as compared with the TCM group (P < 0.05). Hyperkalemia happened less frequently in the TCM group as compared with the other two groups (P = 0.052). Conclusions: For the patients with CKD stage 3, TCM can improve eGFR and hemoglobin with lower side effects. Benazepril significantly decreased the proteinuria. Chinese medicine integrated with benazepril can ameliorate renal function and decrease proteinuria synergistically. (C) 2011 Elsevier Ireland Ltd. All rights reserved.