AbstrakTujuan penelitian ini adalah  mendiskripsikan langkah-langkah model pembelajaran Kooperative  Learning tipe Group Investigation dan mengetahui peningkatkan kerjasama dan hasil belajar. Penelitian ini menggunakan jenis penelitian tindakan kelas. Subjek penelitian ini adalah siswa kelas 4 SD Negeri Mangunsari 05 Salatiga dengan jumlah 40 orang. Teknik pengumpulan data dalam penelitian ini dengan mengunakan tes dan non tes, analisis data menggunakan kuantitatif dan kualitatif. Hasil dari penelitian ini menunjukan bahwa penerapan model pembelajaran pembelajaran Kooperative  Learning tipe Group Investigation dapat meningkatkan kerjasama dan hasil belajar. Hal ini terbukti dengan meningkatnya data  kerjasama  siswa yang diperoleh melalui Penelitian yang dilaksanakan. Hal ini dapat ditunjukan melalui data kondisi awal atau disebut prasiklus siswa dengan rata-rata kerjasama siswa 17,70 dalam  kategori rendah. Setelah dilaksanakan tindakan siklus I dengan model pembelajaran Kooperative learning tipe group investigation mengalami peningkatan, rata-rata kerjasama siklus I yaitu 20,72 dalam kategori cukup. Rata-rata kerjasama siklus II juga mengalami peningkatan dengan jumlah rata-rata 38,25 dan dalam kategori sangat tinggi. Untuk hasil belajar siswa juga meningkat dengan KKM yang ditentukan yaitu 70,  pada tahap kondisi awal (pra siklus), rata-rata hasil belajar siswa adalah 64,50 dengan frekuensi tuntas adalah 9 siswa dengan presentase 22,50% dan frekuesi tidak tuntas 31 dengan presentase 82,50%. Pada siklus I rata-rata hasil belajar siswa meningkat sebanyak 68,50 dengan frekuensi siswa yang tuntas 19 dengan presentase 47,50% dan frekuensi siswa tidak tuntas mencapai 21 dengan presentase 52,50%. Siklus II hasil belajar kembali meningkat sebanyak 84,20 dengan frekuensi jumalah siswa yang tuntas 37 dengan presentase 92,50% dan frekuensi siswa yang tidak tuntas sebanyak 3 dengan presentase 7,50%.  Kata Kunci: Kooperative  Learning , Group Investigation, Kerjasama, Hasil Belajar, IPAAbstractThe purpose of this research is to decribe the steps of a learning model which is Cooperative Learning with Group Investigation type and to find out the improvement of cooperation and study result. This research is using class act type of research. The subjects of this research are 40 students from grade 4 in Mangunsari 05 Public Elementary School in Salatiga. The techniques used in collecting the data for this research was by using test and non-test, and the data analysis used  were quantitative and qualitative. The result of this research shows that the application of Cooperative Learning with Group Investigation type learning model can improve cooperation and study result. This has been proven by the improvement of students’ cooperation data which was obtained through the this research. This can be showed through the data in the early condition or called as students’ pre-cycle with the students’ cooperation average of 17,70 which is included in low category. After the cycle I with the Cooperative Learning with Group Investigation type learning model was done, the data has increased, and the average in cycle 1 was 20,72 which is included in sufficient category. The cooperation average of cycle II also increased with the average number of 38,25 which is included in very high category. Students’ study result also improved, with the determined passing grade 70, on the early condition step (pre-cycle), the average of students’ study result was 64,50 along with the completion frequency of 9 students and the percentage of 22,50% and the incompletion frequency of 31 students with the percentage of 82,50%. On cycle I, the students’ study result has increased as much as 68,50 with the completion frequency of 19 students with 47,50% percentage and incompletion frequency that reached 21 students with 52,50% percentage. On cycle II, the study result increased more as much as 84,20 with the completion frequency of 37 and 92,50% percentage and incompletion frequency of 3 with 7,50% percentage.Keywords: Cooperative Learning, Group Investigation, Cooperation, Study Result, Science