This study focused on the conflict and missional contextualization in Turkey, between Islamism and secularism. This article aims to analyze and relate to the religion of Turkey and Islam, defined what do they cause by conflict and struggle between Islamism and secularism. This study also attempt to apply missional contextualization between Islamism and secularism. Contextualization can be defined as the set of process that yields missional situation in Turkey. It is the process by which Turkey culture become interdependent in aspects of their values, social, economics, and political. It is easy to connect interdependent conflicts through Islamism and secularism in Turkey. The Islamism in Turkey begun by political, social, and cultural motivation with the 19st. This Islamism movement appeals strongly nationalism, liberalism, and modernism in Turkey. This Islamism reveals itself society and community. They are important faith with religion solidarity in their community. The secularism includes Turkey’s constitution, political tradition, social policy, cultural point of view, and religious education. They were complicated the conflict and struggle between Islamism and secularism from a long time in Turkey. The missionary should be consider mission ministry and activity in this Turkey situation. They also careful apply to contextual mission in Turkey. I think that we can be pray to get the Holy Spirit’s support and guide for Turkey’s mission and evangelization.