The effects of BCG-PSN on T-cell subsets and cytokines in vernal conjunctivitis were observed. The level of total IgE was quantitatively determined before and after treatment with BCGPSN by allergen diagnostic instrument in vitro. The content of T-cell subsets of peripheral blood and cytokine were determined by using indirect immune fluorescence method, and IL-4 and INF-γ were quantified by ELISA. The results showed that the level of total IgE was substantially reduced (P＜0.01) after treatment in the BCG-PSN group. Meanwhile, CD8+ was decreased, CD4+ and CD4+/CD8+ratio elevated with significant differences (P＜0. 05) as compared with pre-treatment results. The changes in total IgE, CD+8 ,CD4+ and CD4+/CD+8 ratio after treatment also presented significant differences (P＜0. 05) between BCG-PSN group and routine treatment group. The level of IL-4 in serum declined (P＜0. 05) after treatment in the BCG-PSN group, and INF-γ went up (P＜0.05). IL-4and INF-γ in serum showed significant differences (P＜0. 05) between two groups after treatment.It is concluded that BCG-PSN has a bi-directional immunoregulating effect. It can bring CD4+ and CD+8- into homeostasis, thereby preventing the occurrence of anaphylaxis. At the same time, BCGPSN can restrain Th2, decrease the synthesis of IL-4, switch the balance of Th1/Th2 to Th1 side,boost up the predominance of Th1 relatively, which is propitious to perennial stabilization and recov cry of vernal conjunctivitis.