Abstract: 11 protein zones were isolated from D. farinae extract by PAGE (polyacrylamide gel electrophoresis). 7 of the 11 zone extracts contained allergens, which developed positive reactions in 171 inhalant asthmatics by prick test. Among them, the 6th zone extract was the most sensitive, its positive rate being 49.1%. However, there was no extract which could produce positive reactions in all the patients, and each patient was only sensitive to some, not all of these zone extracts. The number of zones causing positive reactions and the intensity of reactions were quite different from each other. 3 of the 11 zone extracts contained precipitating antigens by CIE but very little allergens. The 6th zone extract which was the most sensitive, didn't contain any precipitating antigen. 21 components of proteins were isolated from D. farinae extract by PAGE. 6 of them contained glycoproteins and 4, lipoproteins. More than 40 components of proteins were isolated from D. farinae extract by SDS-PAGE.