<b><i>Background:</i></b> The role of specific IgE (sIgE) against Der p 1 and Der p 2 in Chinese patients with house dust mite (HDM) allergy has not yet been well investigated. <b><i>Methods:</i></b> One<b> </b>hundred patients were enrolled, based on sensitization and doctor-diagnosed allergy to HDM. Questionnaires were administered to document demographic and clinical characteristics. Serum IgE reactivity to <i>Dermatophagoides pteronyssinus</i> (Dp) extract, Der p 1, Der p 2 and Der p 10 was measured by ImmunoCAP. <b><i>Results:</i></b> Almost all patients were sensitized to Der p 1 (95%) and Der p 2 (93%), with both allergens together being largely responsible for the total anti-HDM IgE response. No evidence for a significant role of Der p 10 was found. Overall, IgE responses to HDM and its 2 major allergens were higher in children than in adults in this cross-sectional study. With increasing age, IgE responses to Der p 2 become more important. A positive correlation was observed between the reaction of sIgE against Dp, Der p 1 and Der p 2 and the number of organs (including the eyes, nose, lungs and skin) that were affected in patients. <b><i>Conclusions:</i></b> In China, Der p 1 and Der p 2 are the dominant allergens in patients with HDM allergy. The relative importance of Der p 1 and Der p 2 changes with age, in favor of Der p 2. Overall, sIgE titers were positively associated with the number of organs affected.