A significant-source of allergens come from house dust that contain particles derived from arthropods, molds, and pet dander. This study evaluated mite and booklouse fauna from vacuumed dust samples in Beijing China (a temperate zone). Our survey was carried out in Beijing in the homes of mite allergic patients who visited our Allergy Department. In total, 38 homes were selected for the collection of dust samples by vacuuming, from December 2008 to January 2010. The flotation method was used to isolate mites from house dust. Permanent slides were prepared for mite specimens and mites were identified and counted under a microscope. In total, 1,798 separate mite and insect specimens were found in 345 dust samples taken from 38 homes. A total of 95 individual Dermatophagoides (D) siboney were detected in 35 dust samples from 19 homes (representing 5.3% of all mite and insect species found in house dust); in addition, this mite was found to co-exist with D. farinae (Hughes, 1961) in 33 dust samples. Our results demonstrated the presence D. siboney that co-existed with D. farinae in house dust in Beijing China (a temperate zone).