The aim of this study was twofold: to investigate (i) the relationship between values, social identities, constructions of European Union (EU) and (ii) reactions to December 12th Copenhagen decision concerning Turkey. In order to fullfil the aim, two methodologically different analyses were carried out: A qualitative analysis of newspapers representing different ideologies, and a quantitative analysis of Turkish university students&amp / #8217 / responses to questionaries. The qualitative analysis revealed different constructions of Turkey&amp / #8217 / s relationship with EU: Advantages of joining the union in terms of human rights and economic development were made in the newspapers as well as disadvantages in terms of emperalism. In additon, historical references to Tanzimat and Islahat decrees were iii made. The quantitative analyses performed on university students&amp / #8217 / responses to questionnaires revealed three social identities: Nationalist-Islam, Turk, and European / three different constructions of EU: Europe As Different, Impermeable Boundaries, and Dissimilar but Advantageous / and two reactions to the decision, Justification and Attribution of decision to Differences and Conflict, as well as negative evaluation of decision. Further analyses revealed that values of patriotism, ethnocentrism, and antisecularism were significant predictors of Nationalist-Islam social identity. Patriotism was a significant predictor of Turk social identity and antisecularism was a significant predictor of European social identity. Seeing EU boundaries as impermeable was related to negative evaluation of the decision and Europe As Different was a significant predictor seeing the decision as a result of differences and conflict. Viewing Europe as dissimilar but advantageous was associated with justifying the decision and ethnocentrism was related to low justification (rejection) of the decision. European and Turk Identity emerged as a significant predictor of the construction of EU. Endorsement of European identity was related negatively to Europe As Different and to seeing EU boundaries as impermeable. High endorsement of European Identity was also negatively related to seeing Europe as dissimilar but advantageous.