Objective To observe the effect of Kechuanning Oral liquid on the expression of P13K in CD4+and CD8+T cells of asthma rats induced by respiratory syncytial virus (RSV), and explore its mechanism of preventing and treating asthma induced by virus. Methods SD rats were randomly divided into phosphate-buffered saline (PBS) control group, model group, dexamethasone and salbutamol group (positive drug group), and Kechuanning oral liquid group. Ovalbumin asthma rats model was built and induced by RSV. CD4+and CD8+T cells were separated by magnetic beads method. The expressive level of PI3K-110αin T cells was detected by immumofluorescence method with flow cytometry. Results Compared with PBS control group, positive drug group and Kechuanning oral liquid group, the CD4+and CD8+T cells percentage and the expression level of PI3K-110α in CD4+ and CD8+T cells of model group were significantly higher. The differences were statistically significant (P<0.01). The CD4+and CD8+T cells percentage was not associated with the expression level of PI3K-110α in CD4+ and CD8+T cells of each group by Pearson correlation analysis. Conclusion The CD4+ and CD8+T cells involve in the asthma immunity balanced modulation, and the level of PI3K expressed by CD4+ and CD8+T cells increase distinctly. Kechuanning oral liquid can restrain the expression of PI3K in CD4+ and CD8+T cells, which might be one of the immunologic mechanisms of treating asthma.