Allergy is an immune disease including asthma. Activation of Th2 response, such as production of IL-4, IL-5 and IL-13 from CD4+ T cells and IgG1 or IgE from B cells is responsible for allergy. Activation of acquired immune system requires preceding activation of innate immunity, therefore innate immunity may control Th2 response and allergy. Recent studies revealed that dendritic cells, epithelial cells, and basophils play central roles in the initiation of Th2 response. In this review, we will summarize the current understanding on the control of Th2 and allergic responses by innate immune system, and discuss recent findings on house dust mite-induced allergic response based on these understandings.