The percentage of peripheral blood CD4 + CD28 - T cell in 59 patients with autoimmune hepatitis (AIH) (36 with active disease and 23 stable) and 30 normal individuals was evaluated by twocolor flowcytometry. IL-10 and TNF-α levels were assayed by double-antibody sandwich ELISA. Serum immunoglobulin were also analyzed. Patient with active AIH had significantly higher peripheral blood CD4 + CD28 - T cell and TNF-α levels than normal individuals ( P ＜ 0. 05 ), while in patients with remission they were only slightly higher than normal controls. If remission was induced in patients with active AIH,peripheral blood CD4 + CD28 - T cell percentage would be significantly reduced ( P ＜ 0. 05 ) while IL-10 increased ( P ＜ 0. 05 ). The percentage of peripheral blood CD4 + CD28 - T cell in patients with relapse was significantly higher than newly diagnosed patients and normal controls; Peripheral blood CD4 + CD28 -T cell percentage in patients with abnormal serum immunoglobulin ( IgA, IgG and IgM ) levels was significantly higher than those with normal levels and normal controls. We concluded that abnormal peripheral blood CD4 + CD28- T cells and cytokine in patients with AIH may be related to disease activity and clinical manifestations, which may also play a role in the pathogenesis of AIH.