Objective To search for the changes of T cells subpopulations and immunoglobulin and their relation-ship in children patients with simple nephrotic syndrome. Design Case-control research. Patients aud Participants 39 patients with simple nephrotic syndrome were divided into two groups:the incipient group and relapse group (6 cases were determined at the incipient and relapse time) .Thereare 28 patients in incipient group, 19 males and 9 females, at the age of 2 to 10 years old. There are20 patients in relapse group, 12 males and 8 females, at the age of 3 to 13 years old. There are 35health children in control group, 21 males and 14 females, 2～13 years old. Interventions T cells subpopulations were determined by indirect immunofluorescence of OKT linesmonoclonal antibodies. The serum IgG was determined by routine simple agar immunodiffusion tests. Results and Conclusions The CD_3~+ and CD_4~+ cells are of no change in the children patients withsimple nephrotic syndrome, and the CD_8~+ and CD_(10)~+ cells are obviously increased, the Values of CD_4~+/CD_8~+ are obviously lower than those in the control qroup, there are no difference between the incipientand relapse groups. The levels of serum IgG were decreased in the 85.3% children patients, IgM were inc-reased in 29.4% of that. The values of CD_4~+/CD_8~+ have positive correlation and negative correlationwith the levels of serum IgG and IgM respectively.