Abstract: This research aims to know: (1) the difference of ability to understand science concept between students who were taught by Two Stay Two Stray model and students who were taught by Student Teams Achievement Division model, (2) the difference of ability to understand science concept between students who had high learning motivation and students who had low learning motivation; (3) interaction between learning model and learning motivation toward the ability to understand science concept.This research includes a quantitative experimental study with 2x2 factorial designs. The population was the fifth grade elementary school in Wonogiri subdistrict. The sample of this research were SD Negeri 1 Wonoboyo and SD Negeri 2 Wonoboyo. The collected data analyzed by using Analysis of Variance Two-Way with different cells. The result of this research were: (1) there was the difference of ability to understand science concept between students who were taught by Two Stay Two Stray model and students who were taught by Student Teams Achievement Division model, (2) there was the difference of ability to understand science concept between students who had high learning motivation and students who had low learning motivation, (3) interaction between learning model and learning motivation toward the ability to understand the science concept. Abstrak: Penelitian ini bertujuan untuk mengetahui: (1) perbedaan kemampuan memahami konsep IPA antara siswa yang diajar dengan model pembelajaran Two Stay Two Stray (TSTS) dan siswa yang diajar dengan model pembelajaran Student Teams Achievement Division (STAD), (2) perbedaan kemampuan memahami konsep IPA antara siswa yang memiliki motivasi belajar tinggi dan siswa yang memiliki motivasi belajar rendah, (3) interaksi antara model pembelajaran dan motivasi belajar terhadap kemampuan memahami konsep IPA. Penelitian ini termasuk penelitian kuantitatif eksperimental dengan desain penelitian 2x2 faktorial. Populasi dalam penelitian ini meliputi siswa kelas V SD Negeri di Kecamatan Wonogiri. Sampel dalam penelitian ini adalah SD Negeri 1 Wonoboyo dan SD Negeri 2 Wonoboyo. Teknik analisis data yang digunakan adalah Analisis Variansi Dua Jalan dengan Sel Tak Sama. Hasil penelitian ini adalah: (1) ada perbedaan kemampuan memahami konsep IPA antara siswa yang diajar dengan model pembelajaran Two Stay Two Stray (TSTS) dan siswa yang diajar dengan model pembelajaran Student Teams Achievement Division (STAD), (2) ada perbedaan kemampuan memahami konsep IPA antara siswa yang memiliki motivasi belajar tinggi dan siswa yang memiliki motivasi belajar rendah, (3) ada interaksi antara model pembelajaran dan motivasi belajar terhadap kemampuan memahami konsep IPA. Kata kunci: Two Stay Two Stray, Student Teams Achievement Division, motivasi belajar, kemampuan memahami, konsep IPA
