Berdasarkan hasil observasi di kelas VIII SMP pada salah satu sekolah swasta di Makassar, peneliti menemukan kebanyakan siswa memiliki pemahaman konseptual yang rendah pada mata pelajaran IPS Terpadu. Dalam belajar, siswa hanya bergantung pada informasi yang disampaikan guru tanpa benar-benar memahami konsep pembelajaran tersebut. Peneliti kemudian memutuskan untuk menerapkan metode Problem-Based Learning sebagai upaya untuk meningkatkan pemahaman konsep siswa. Penelitian ini menggunakan metode Penelitian Tindakan Kelas (PTK) model Spiral Kemmis & Taggart. Penelitian dilakukan sejak tanggal 2 September 2015 hingga 10 Oktober 2015. Penelitian dilaksanakan sebanyak dua siklus dengan melibatkan 20 orang siswa. Hasil data dianalisis dengan menggunakan teknik analisis deskriptif kualitatif dengan menggunakan instrumen berupa lembar panduan wawancara guru mata pelajaran, lembar angket siswa, catatan lapangan peneliti, dan lembar kerja siswa. Hasil penelitian menunjukkan adanya peningkatan pemahaman siswa. Peneliti menyimpulkan bahwa pembelajaran dengan menggunakan metode Problem-Based Learning dapat meningkatkan pemahaman konsep siswa pada mata pelajaran IPS Terpadu kelas VIII melalui tahapan-tahapan seperti penemuan masalah, pembagian tugas dalam kelompok, melakukan kajian independen, bertukar informasi, menyajikan solusi, dan melakukan evaluasi dan refleksi terhadap hasil kegiatan pembelajaran. Dalam setiap tahapan guru berperan sebagai fasilitator. / Based on observation of researcher which was done at one of a private school in Makassar, it was found that most of the students had low conceptual understanding in Social Science studies. The student rely only on the information given by teacher without really understanding the concept of the learning. Thus, the researcher decided to implement Problem-Based Learning method in order to improve students’ conceptual understanding. The method of this research is a Clasroom Action Research (CAR) spiral model of Kemmis & Taggart. The research was conducted from September 2 to October 10, 2015, consisted of two cycles involving 20 students. The qualitative descriptive analysis was used to analyze the data. Theinstrument used in this research were subject teacher’s interview guidance sheet, student questionnaire sheet, researcher’s field notes, and student worksheet. The research shows that there was improvement in students’ conceptual understanding. The researcher concluded that using Problem-Based Learning method in learning can improve students’ conceptual understanding in Social Science studies through steps such as discovery of the problem, the division of tasks in groups, conduct independent studies, exchange information, presenting solutions, and conduct evaluation and reflection on the results of learning activities. In every stage of Problem-Based Learning method, the teacher provide guidance as facilitator.