Media is one of the most important sources of identity-building in the modern era. But there are two viewpoints about its impact on the identity of subjects. One of them regards the subject as a passive entity towards media identity discourse. The other considers a more active role for subjects and believes in identity resistance. Given media diversity and multiplicity at the world scale and the subject's choosing power, on the basis of the second viewpoint, the researchers have examined mass media's impact on the collective identity among high school students in Yasouj. According to the findings of this research, national and provincial televisions are at the top of the media used by respondents, and ethnic, national and global identities are placed at their collective identity prominence respectively. Meanwhile neither all media have similar impacts on a kind of collective identity and nor a single media has similar impact on various kinds of collective identity. Also findings indicate that the students' ethnic identity has been paralleled with reinforcing national identity and weakening their global identity.