This study was conducted to provide basic knowledge of effective environmental control of patients with allergic rhinitis during the period of July to December 1995. The subjects were consisted of 29 patients with allergic rhinitis. Each patient of nasal symptom scores assessed and dust samples drowned from their bedrooms twice for 1 month interval. The data. 58 samples were analyzed by using ANOVA. t-test and stepwise multiple regression. The results were as follows 1. Out of a total 52 dust samples $(89.7\%)$ were isolated house mites. Total 815mites/0.5gm dust were collected and identified the most prevalent house mites was Pyroglypidae mite with $81.1\%$ 2. The amount of house dust mites in the group of bedding laundry with hot water was significantly lower than that those of with cold water. 3. The nasal symptoms of the patients in the group of bedding laundry with hot water was significantly less than that those of with cold water. and also those of using large size bedroom was significantly lower than that those of using small size one. The nasal symptoms of the patients was closely associated with the washing water temperature. bedroom size. bedroom temperature. type of bedclothes, and frequency of cleanig room.