The social information processing model suggests that the overall conduct of a person is the product of situational cues and past experiences. Likewise, a student who is new to on-campus life perceives his surroundings and social interactions according to the previous positive or negative social experiences. This research aimed to examine the relationship of perceived ethnic discrimination, temperamental characteristics, and bullying behavior (verbal, non-verbal, or bullying perpetration) among university hostilities. A purposive sampling strategy was used to recruit 635 university hostilities who belonged to on-campus’s ethnic minority groups. Constructs were analyzed by the Adult Temperament Questionnaire (self-report), Illinois Bully Scale (Teacher’s Version), and Perceived Ethnic Discrimination Questionnaire Community Version (Self-report). The results suggested that two dimensions of perceived discrimination (place discrimination and perceived exclusion) acted as mediators between temperamental characteristics (Effortful control, negative affect, and extraversion) and types of bullying (physical, non-physical, and bullying perpetration).