Objective To observe the clinical characteristics and prognosis of primary nephrotic syndrome (PNS) in the elderly. Methods The clinical and pathological features of 52 elderly patients with PNS and 64 non-elderly patients with PNS were retrospectively analyzed and compared.The elderly patients with PNS received routine treatment:oral corticosteroids prednisone 1mg·kg-1 ·d-1.After 8 weeks maintenance treatment,if symptoms were alleviated,the prednisone dose was gradually reduced to a maintenance dose, then was stopped gradually. If symptoms were not alleviated, the cyclophosphamide or cyclosporine, mycophenolate mofetil was added. Results There were significant differences in the numbers of patients complicated with hypertension, infection,chronic renal insufficiency and hematuria between the elderly group and non-elderly group (P＜0. 05＝.But there were no significant differences in the level of blood albumin, quantitative measurement of 24 hours urinary protein and incidence rate of acute renal insufficiency between the two groups (P＞0.05). The major pathological types of PNS in the elderly were membranous nephropathy (46.2 %),IgA nephropathy (23. 1 %) and focal segmental glomerulosclerosis ( 11.5 %), respectively. And the major pathological types of PNS in non-elderly group were mesangial proliferative glomerulonephritis (32.8%), IgA nephropathy ( 25.0% ) and minimal change nephropathy ( 20. 3 %), respectively.Complete remission after treatment was found in 31 patients(59.6%), partial remission in 18 cases and inefficacy in 3 cases. Conclusions The major clinicopathological type of PNS in the elderly is membranous nephropathy and should be treated using corticosteroids and immunosuppressive agents,with different effects in different pathological types.