The problem underlying the research is that science process skills in learning, especially the subject of science and science on electricity in grade 5 of SDN Sindangreret are still relatively low. The purpose of this study is to improve science process skills by implementing the Project Based Learning (PJBL) learning model. The research method used in this study is Classroom Action Research (CAR) model of Kemmis and McTaggart with research subjects of 26 grade 5 students. The implementation was carried out through two learning cycles with stages of planning, implementation, observation, and reflection. Data were collected using observation sheets of students' science process skills with analysis of the percentage of achievement categorized as very good (86-100%), good (76-85%), moderate (60-75%), low (55-59%), very low (?-55%). The results showed an increase in science process skills from pre-action 38.46% to 69.23% in cycle I and reached 88.46% in cycle II. The PJBL model proved to be collaborative and independent knowledge formation. The implementation of the PJBL model has a positive impact on various aspects of learning, including students' cognitive, affective, and psychomotor skills. The PJBL model encourages meaningful learning because students play an active role in the process of discovering and constructing knowledge. Based on the test results, it shows that there is an increase in science process skills from the pre-action phase, to cycle I to cycle II. Therefore, it can be concluded that the implementation of the PJBL learning model can improve science process skills in grade 5 of SDN Sindangreret, Cipawitra District in the 2025/2026 academic year. ABSTRAKMasalah yang melatarbelakangi penelitian adalah keterampilan proses sains dalam pembelajaran khususnya mata pelajaran IPAS materi listrik di kelas 5 SDN Sindangreret yang masih tergolong rendah. Tujuan penelitian ini adalah meningkatkan keterampilan proses sains dengan menerapkan model pembelajaran Project Based Learning (PJBL). Metode penelitian yang digunakan dalam penelitian ini adalah Penelitian Tindakan Kelas (PTK) model Kemmis dan McTaggart dengan subjek penelitian 26 siswa kelas 5. Penerapan dilakukan melalui dua siklus pembelajaran dengan tahapan perencanaan, pelaksanaan, observasi, dan refleksi. Data dikumpulkan menggunakan lembar observasi keterampilan proses sains siswa dengan analisis persentase capaian berkategori sangat baik (86-100%), baik (76-85%), sedang (60-75%), rendah (55-59%), sangat rendah (?-55%). Hasil penelitian memperlihatkan adanya peningkatan keterampilan proses sains dari pratindakan 38,46% menjadi 69,23% pada siklus I dan mencapai 88,46% pada siklus II. Model PJBL terbukti kolaboratif dan pembentukan pengetahuan mandiri. Penerapan model PJBL memberikan dampak positif terhadap berbagai aspek pembelajaran, baik dari kognitif, afektif, maupun psikomotorik siswa. Model pjbl mendorong pembelajaran yang bermakna karena siswa berperan aktif dalam proses pencarian dan pembangunan pengetahuan. Berdasarkan hasil tes menunjukkan bahwa adanya peningkatan keterampilan proses sains dari mulai pratindakan, ke siklus I sampai siklus II. Maka dapat disimpulkan bahwa penerapan model pembelajaran PJBL dapat meningkatkan keterampilan proses sains di kelas 5 SDN Sindangreret Kecamatan Cipawitra Tahun Ajaran 2025/2026.