To evaluate the effect of Qing-wen Granule (QWG) on immunological function, T lymphocyte subsets and interferon gamma(INF-gamma) expression cells in peripheral blood mononuclear cells, lymphocyte transformation rate and the level of salivary secretory IgA (sIgA) were determined by alkaline phosphatase antialkaline phosphatase (APAAP) technique or 3H-TdR incorporation with lymphocyte stimulation index(SI) or agar single immunodiffusion in infantile respiratory viral infection. The results showed that the percentage of CD3, CD4, and CD4/CD8 ratio of patients treated with QWG for 3 days were not significantly different in comparing with the control group untreated with QWG (P > 0.05), but the values of IFN-gamma expression cell, SI and the level of sIgA were more markedly increased than that of control (P < 0.05). It suggested that the QWG could improve and regulate immune function in infantile respiratory viral infection.