The secretion of IL-10 by NKT cell in asthma group patients decreased (P < 0.01), especially at 48 h, while IL-10 in SIT group increased significantly compared with asthma patients (P < 0.01), and there was no significant difference in IL-10 secretion between normal control group and SIT group (P > 0.05). This evidence concerns the gene IL10 and asthma.