Objective: To study the function of cellular immunity in patients with hyper-IgE syndrome (HIE). Methods:T-lymphocyte subtypes of the peripheral blood and cutaneous delayed-type hypersensitivity (DTH) response to two recall antigens, tetanus toxoid (TT) and purified protein derivative(PPD), were measured in five patients with HIE and 15 healthy controls, respectively. Results: The CD4+ cell counts in HIE group were significantly lower than those in control group ( P ＜ 0.01). In contrast, CD8 + cells were significantly higher than those in the control ( P ＜ 0.01). The induration sizes of DTH response to two recall antigens were smaller in HIE group than those in the control group ( P ＜ 0.01 ). Conclusion: There was an immunologic dysfunction of T lymphocytes in the patients with HIE.