The purposes of the study is to examine the relationship between developmental assets, stress and risk behaviors of university students. The subject of the study is 1023 university students. Questionnaire organized by scales of developmental assets, stress and risk behaviors was used. The major findings were as follows; First, internal assets made direct effects on stress and risk behaviors. External assets made direct effects on stress. Second, mediating effects of stress were statistically significant in relations between developmental assets and risk behaviors. External assets were complete mediating effects by making effects indirectly on risk behaviors through the stress. Internal assets showed partial mediating effects.