The purpose of this research is to investigate the synergistic effect of herb medicines with hydrocortisone and the regulation effect on the immune system of Onbitang and Dangguijakyaksan at the supernatant of PHA-P stimulated PBMC in the patients with minimal change nephrotic syndrome(MCNS). From the measurement of the concentration rate of IL-4, sCD23 and IL-13, the experiment yielded the following results : The Onbitang group showed a greater tendency to suppress IL-4 and IL-13 levels in MCNS group with no statistical significance. It showed very strong suppression in soluble CD23 compared with control group in MCNS group. The Dangguijakyaksan group, though not statistically significant, was inclined to suppress IL-4 level in MCNS group. It shows stronger suppression in sCD23 and IL-13 levels than these of control group in MCNS group. As for the synergistic effect, the group of hydrocortisone with herb medicines(Onbitang or Danguijakyaksan) produced more suppressive effect to IL-13 level in MCNS group than that of hydrocortisone-only group. They also tended to suppress sCD23 and IL-4 levels, though no statistical significance can be given. As to the suppressive effect of 1L-13 level, the group of Onbitang with hydrocortisone showed an increase of 22.6%, while the group of Dangguijakyaksan with hydrocortisone showed 14.7%. So Onbitang is more effective than Dangguijakyaksan. From the above results, a combinative treatment(herb medicines with hydrocortisone) can be an alternative method to substitute for steroid therapy. It can be a more effective therapy than steroid-only therapy because it is expected to reduce side effects and it shows more special effect to suppress IL-13 level. Based on the present results, further investigation concerning the serum IgE elevation is needed.