Community study of atopic dermatitis in school children in Izumo City was performed. The percentage of atopic dermatitis was 7.5 % at the school periodic health screening in 1989, and that of the past history was 37.8%. In the related factors caused atopic dermatitis, the family history, dust and food (egg and tofu) were proved statistically. As the number of mites on the mat in the living room increased, the percentage of the past history of atopic dermatitis was higher. The present study showed that the causes in atopic dermatitis were multifactorical, and the change of our complex life style and the environment should be studied epidemiologically to prevent the atopic dermatitis.