Islamic religion teachers have significant role in forming their student's religious views and attitudes, especially in the level of senior high school since high school student are in the middle of identity seeking process. But it can be threat if teacher religious attitude are lead to radicalism, while radicalism associated with anti-nationalism. This descriptive quantitative study conducted in Semarang city and involving 47 schools. Samples selected are 47 Islamic religion teachers. Results shows that 97.9% of them regard non-moslem as their comrades, and willing to cooperate in social activities (97.9%), economic (93.6%), and politic (74.5%). While in terms of nationalism, there are 2.1% respondents believe that NKRI (The Unitary State of the Republic of Indonesia) is not suitable form of state, and 4.3% judge that Pancasila is not the right ideology. And 8.7% suppose that Khilafah is the most appropriate form for Indonesia.