<p>【Objectives】 It has been considered that Kireru behaviours would be happened among elementary and junior school students. However, a recent study reported that some elder students have a high desire for violence, particularly male university students. This study examined how the intensity of aggressiveness or emotional self-regulation, which are considered to form a part of emotional intelligence, relate to ‘kireru’ , aiming to obtain basic data on the prevention of ‘kireru’.</p><p>【Methods】 Participants were 348 university students (135 male and 213 female) who completed our questionnaires. They responded to the Buss-Perry Aggression Questionnaire (BAQ) and a questionnaire assessing emotional competence and ‘kire’ behaviours. In this study, scores on the BAQ were interpreted as follows: Aggression levels were indicated by the average BAQ score quartile, namely, low, high, and moderate.</p><p>【Results】 The male students scored significantly higher than the female students on total BAQ. The male students scored significantly higher in ‘kire’ behaviours of ‘direct attack’ (p＜0.05) and ‘asocial behaviour’ (p＜0.05) the female students. Furthermore, the male students exhibited a significant interaction between sex and aggression levels on ‘kire’ behaviours of ‘direct attack’ (F(2,342) ＝4.27; p＜0.05) and ‘asocial behaviour’ (F(2,342) ＝7.51; p＜0.05) in an ANOVA. </p><p>The female students scored significantly higher on ‘control of emotion’ (p＜0.05) and ‘panic’ (p＜0.05) than did the male students. Furthermore, the female students exhibited a significant interaction between sex and aggression levels on ‘kire’ behaviours of ‘panic’ (F(2,342) ＝ 4.59;p＜0.01) in an ANOVA. </p><p>　It was possible that the male students were higher in aggression or direct attack than the female students. Further, the male students who had low levels of aggression tended to express asocial behaviour. However, the female students were high in emotional competence as emotion regulation, espesically, ‘control of emotion’ was high regardless of degree of aggression. But it was possible that the female students may have expressed panic without emotional control when the intensity of aggressiveness was high.</p><p>【Conclusions】 It is suggested that there are more differences for aggression or aggressive behaviour and emotional competence in male and female university students.</p>