The effect of aqueous extracts of medicinal plants $AMP-365^{TM}$ was tested for immune system regulating activity based on anti-inflammatory activity, anti-oxidant, macrophage proliferation and T-lymphocyte proliferation activity. $AMP-365^{TM}$ dose-dependently increased proliferation of RAW264.7 macrophage cells and its nitric oxide production as well as DPPH radical scavenging activity. On the other hand, T-lymphocyte proliferation activity was decreased on dose-dependent manner. Passive cutaneous anaphylaxis reaction was alleviated by 49% by administering 250 mg/kg of $AMP-365^{TM}$. The results suggest that $AMP-365^{TM}$ can be beneficial in the treatment of immediate allergic reactions as an adjuvant supplement material.