The prevalence of atopic dermatitis has markedly increased in recent years but the mechanism has not been clearly revealed. Recent study exhibited that atopic dermatitis was exacerbated by the increase of proteinase-activated receptor (PAR)-2 expression, which activated $I{kappa}B$ kinase --> nuclear factor kappa B. Therefore, we determined whether the allergens of dust mites induced the expression of PAR-2, intercellular adhesion molecule-1 (ICAM-1, adehision molecule), interleukins (IL)-6 in HaCaT keratocytes and which herbal 1,3-butylene glycol extracts (Mori Cortex Radicis, Sanguisorba officinalis L., Arctium lappa Linne, Torilis japonica DC, Melia azedarach Linne var. japoinca Makino) suppressed their expression. Dust mite allergen increased PAR-2, ICAM-1 and IL-6 expression in HaCaT cells in a dose-dependent manner up to $3{mu}g/mL$ but their expression reached the plateau over the dosages. The allergen ($3{mu}g/mL$) also secreted more cytokines such as tumor necrosis factor (TNF)-${alpha}$ and IL-6 into the media. Among five different herbal extracts ($50{mu}g/mL$), Mori Cortex Radicis and Sanguisorba officinalis L. suppressed the PAR-2, ICAM-1 and IL-6 expression in HaCaT cells, which was activated by dust mite allergen ($3{mu}g/mL$) and they also reduced the secretion of TNF-${alpha}$ and IL-6 into the media. In conclusion, Mori Cortex Radicis and Sanguisorba officinalis L. can effectively reduce the prevalence and progression of atopic dermatitis by dute mite allergen.