There have been several studies on children's image of peace. Though they have taken up sex as an independent variable, it has not been clear whether sex is a significant variable accounting for differences in children's image of peace The present paper examines sex differences in university students' image of peace on the basis of an association test conducted in 1982. The result shows that i) male students' responses are more variegated than female students', and conversely, female students' responses are more stereotyped than male students', ii) there is no sex differences in the 'meaningfulness' of the Japanese word 'heiwa' which roughly corresponds to the English 'peace', iii) there are many response words which show sex difference in the rate of response, and concerning these words, female responses are semantically characterized by the dominance of 'positive peace' while male responses are characterized by that of 'negative peace', iv) there is no significant sex difference in the basic structure of peace image as a whole in that, both with males and with females, the peace image consists of two components, that is, 'positive peace' and 'negative peace'.