As the most common inflammatory skin disease in children, atopic dermatitis begins in infancy or early childhood, with about 90% of cases appearing under age of 5. The prevalence of atopic dermatitis has rapidly increased among children in recent years. Physiological and psychological abnormalities and social impact are also well known in children with atopic dermatitis and in their families. Atopic dermatitis not only seriously affects the quality of life of the children and their families but also is leading chronic disease in children with hard-to-cure.Recently, we found that the fermented extract of several plants had considerable potential to treat juvenile atopic dermatitis. This extract therefore is now under investigation to find the underlying immunopathological mechanism by determining its inhibitory effects on nitric oxide (NO) release and T cell proliferation. The fermented extract dose dependently blocked NO production. In particular, the inhibitory effect of the extract was maximized up until 80-fold dilution of the original extract. This extract did not induce cytotoxic effects up to 80-fold dilution. Interestingly, doses between 320- and 80-fold dilution significantly protected cell death mediated by LPS-induced NO production. The fermented extract also significantly suppressed CD3 induced T cell proliferation in a dose dependent manner.