The present study was conducted to discuss several problems in studying persuasive effects under irrelevant fear-arousing situations. The following conclusions were arrived at.(1) Studies of persuasive communications under irrelevant fear-arousing situations and studies of fear-arousing communications have dealt with quite different kinds of fear-arousal. (2) Since the previous studies were based only on immediate persuasive effects, and have presumed that irrelevant fear-arousal facilitated persuasive effects, such persuasion facilitating effects were interpreted as apparent effects lacking durability. For this reason, it is important that we measure not only immediate persuasive effects but also delayed ones. (3) It is also desirable to compare the effects of persuasive communications under irrelevant fear-arousing situations with the effects of fear-arousing communications in order to more precisely examine the former effects. (4) As there were no empirical studies on the mechanisms of persuasion facilitating effects induced by irrelevant fear-arousal, we must investigate these mechanisms primarily in relation to the distraction hypothesis. (5) In the present paper we classified three types of procedures used in manipulating the relevance between persuasion topics and feararousing content, and we have pointed out that these three manipulating procedures have both merits and demerits.