An intraventricular administration of sulpiride suppressed the experimental cinchophen ulcer, thereby the effect of repeated administration of the material on cinchophen ulcerogenesis is evident, whereas intermittent administration lacked this effect. Such an effect as reducing experimental cinchophen ulceration, which is due to central neurohumoral mechanism, following intraventricular infusion of sulpiride appears to be ascribable to a chemical blockage of the hypothalamic structure. It can thus be concluded that sulpiride acts principally at the level of hypothalamus. Its inhibitory action on cinchophen gastric ulcer development is probably exerted via the hypothalomo-pituitary-adrenal axis, which is essential to the occurrence of an ulcer, and may be regarded as favoring the central neurohumoral theory of cinchophen ulcerogenesis.