Pemahaman konsep ekonomi siswa kelas X SMA Negeri 2 Slawi pada materi Lembaga Keuangan Bukan Bank (LKBB) masih rendah, ditandai dengan tingginya miskonsepsi dan kesulitan siswa mengaitkan konsep dengan penerapan nyata akibat dominasi metode ceramah dalam pembelajaran. Penelitian ini bertujuan untuk menguji efektivitas model problem based learning (PBL) berbantuan mind mapping terhadap kemampuan rekonstruksi konsep siswa. Penelitian menggunakan metode eksperimen dengan desain quasi-experimental Nonequivalent Control Group Design. Sampel ditentukan melalui purposive cluster sampling, yaitu kelas X.7 sebagai kelas eksperimen (35 siswa) yang menerapkan PBL berbantuan mind mapping dan kelas X.1 sebagai kelas kontrol (36 siswa) yang menerapkan PBL murni. Data dikumpulkan melalui tes uraian berjumlah 12 butir yang disusun berdasarkan empat dimensi perubahan konseptual Suparno (2019). Hasil uji Independent Sample T-Test pada data posttest menunjukkan nilai t = 4,895 dan signifikansi 0,000 < 0,05, dengan rata-rata posttest kelas eksperimen (44,71) lebih tinggi dibandingkan kelas kontrol (36,17). Temuan ini diperkuat oleh skor N-Gain kelas eksperimen sebesar 0,483 (kategori sedang), lebih tinggi daripada kelas kontrol sebesar 0,116 (kategori rendah). Disimpulkan bahwa model PBL berbantuan mind mapping efektif dan terbukti lebih unggul dibandingkan PBL murni dalam meningkatkan kemampuan rekonstruksi konsep ekonomi siswa SMA. Abstract Students' conceptual understanding of economics, particularly regarding Non-Bank Financial Institutions (LKBB), remains low among grade X students of SMA Negeri 2 Slawi, marked by widespread misconceptions and difficulty relating concepts to real-life application due to the dominance of lecture-based teaching. This study aims to examine the effectiveness of problem based learning (PBL) assisted by mind mapping on students' concept reconstruction ability. The study employed an experimental method with a quasi-experimental Nonequivalent Control Group Design. The sample was determined through purposive cluster sampling: class X.7 as the experimental group (35 students) applying PBL assisted by mind mapping, and class X.1 as the control group (36 students) applying PBL alone. Data were collected using a 12-item essay test developed from Suparno's (2019) four dimensions of conceptual change. The Independent Sample T-Test on posttest data yielded t = 4.895 with a significance of 0.000 < 0.05, with the experimental class posttest mean (44.71) higher than the control class (36.17). This finding was reinforced by the N-Gain score of the experimental class (0.483, moderate category), higher than the control class (0.116, low category). It is concluded that PBL assisted by mind mapping is effective and superior to PBL alone in improving students' economic concept reconstruction ability.