OBJECTIVE: To investigate the risk factors for hospital acquired pneumonia(HAP) in children with the nephrotic syndrome(NS).METHODS: Clinical data of 198 children with NS admitted between December,1997 and December, 2000 were analyzed retrospectively. RESULTS: Of the 198 cases, 63 had nosocomial infection(31.8%), including 33 cases of HAP(52.3%), accounting for the largest percentage of nosocomial infection. There was no difference between the HAP children and non-infection children with respect to age, course of disease, sex, clinical type of NS, leucocyte count, serum IgA, IgM ,and BUN levels, and 24 h urine protein quantity. Duration of hospitalization before acquiring nosocomial infection was longer [(44.6±7.6) days vs((23.9±9.3)days, the percentage of patients with severe edema(51.5% vs 26.8%) and immunosuppressive agent administration was higher(45.5% vs 19.1%), and the serum albumin and IgG levels were lower [(11.46±3.37) g/L vs(22.91±8.67) g/L and(2.72±1.32) g/L vs(6.81±1.89)g/L ,respectively] in HAP children copmpared to those non infection children(all P < 0.05). CONCLUSIONS: Severe edema, reduced levels of serum albumin and IgG, use of immunosuppressive agent, a nd longer hospitalization duration may be risk factors for HAP in childre n with NS.