Berdasarkan pengamatan yang peneliti lakukan di kelas XI-IPS, peneliti menemukan siswa kurang aktif dalam proses pembelajaran di kelas. Ketika peneliti berusaha untuk menciptakan pembelajaran yang interaktif, hanya ada beberapa siswa yang berinisiatif menjawab, bertanya dan mengemukakan pendapat selama pembelajaran. Untuk mengatasi masalah tersebut, peneliti kemudian melakukan penelitian dengan menerapkan metode Numbered Heads Together (NHT) dalam pembelajaran. Adapun tujuan penelitian ini adalah untuk meningkatkan keaktifan siswa melalui penerapan metode NHT. Metode penelitian yang digunakan adalah Penelitian Tindakan Kelas (PTK) model spiral dari Kemmis dan Taggart. Penelitian dilakukan pada 22 September sampai 20 Oktober 2014 pada 27 siswa dalam tiga siklus. Pengumpulan data dilakukan dengan menggunakan beberapa instrumen berupa lembar observasi dan kuesioner siswa yang akan dianalisis dengan menggunakan perhitungan statistik sederhana, serta lembar wawancara guru mentor yang akan dianalisis secara deskriptif kualitatif. Berdasarkan hasil penelitian, dapat disimpulkan bahwa penerapan metode Numbered Heads Together (NHT) melalui kelima langkahnya dapat meningkatkan keaktifan . / Based on observation done by the researcher in XI-IPS class, the researcher found that the students were not active during their learning process in the classroom. When researcher tried to make an interactive learning, there were only several students were having initiative to answer, ask, and deliver opinion during learning process in class. In order to overcome that problem, Researcher did a research on implementing the Number Heads Together (NHT) method in learning process. The purpose of this research is to increase the students’ activeness through the application of NHT method. The research method that used was Classroom Action Research (CAR) model spiral from Kemmis and Taggart. The research was done in September 22nd, 2014 until October 20th, 2014 to 27 students with three cycles. Data were collected using instruments which were observation sheet, questionnaires that would be analyzed using simple statistics calculation, and interview mentor teacher that would be analyzed descriptively qualitative. Based on the research, the reasearcher concludes that the application of Numbered Heads Together (NHT) method through the five steps can increase activeness