1. The new patients of so called secondary epidemy of infectaous hepatitis were chiefly those who had been listed as the patients of latent hepatitis or inapparent infection in the previous epidemy. 2. In fairly great number of cases in which the patients were listed as inapparent infection, patients complained trifling subjective symptoms and later they were suspected as of slight abortive form. In the cases of compiaining subjective symptoms as well as in the cases of having no complaint, the percentage of onset was approximately the same. In case of infectious hepatitis, it is considered that the germs may have same slight responsive effect upon the patient after infected, or sometimes may have no effect for considerablly long time, but as the physical strength declines, the germs show their special quality of causing the apparent symptoms.