Atopic dermatitis (AD) is a chronic inflammatory skin disease, which requires safe and effective treatment. In this study, we evaluated the effects of SSC201, a herbal formulation consisting of Stemonae Radix, Spirodelae Herba, and Cnidii Fructus, on the development of AD induced by 2,4-dinitrochlorobenzene in the NC/Nga murine model. Oral administration of SSC201 significantly reduced the severity of dermatitis and the tendency of mice to scratch their lesions. SSC201 significantly reduced the thickening of the epidermis/dermis and the infiltration of T cells, eosinophils, and mast cells into the dermis. These results were supported by findings of reduced numbers of CD4(+), CCR3(+), and CD117(+)FcɛRIα(+) cells in the skin. Furthermore, SSC201 significantly decreased the number of CD4(+), CD8(+), and CD3(+)CD69(+) T cells in lymph nodes. SSC201 not only decreased the plasma levels of immunoglobulin E (IgE) and the numbers of IgE-producing B cells (B220(+)CD23(+)), but also reduced the number of eosinophils and the levels of eotaxin as well as concentrations of thymus and activation-regulated chemokine in the periphery. Splenic levels of Th2 cytokines, including interleukin (IL)-4, IL-5, and IL-13, were reduced, whereas the levels of IL-12, a Th1 cytokine, were increased. Taken together, our data suggest that SSC201 may be an effective therapeutic agent for the treatment of AD.