Skeleton Puppet is an instructional learning medium in the form of a human skeletal model with movable bones and joints. This study employed the Classroom Action Research (CAR) method. The research was conducted at SD Negeri 098 Pidoli, Panyabungan District, Mandailing Natal Regency, involving sixth-grade students.The objectives of this study were to determine whether the Skeleton Puppet learning media could improve sixth-grade students' understanding of the humanskeletal system and joints, and to analyze how the implementation of the Skeleton Puppet innovation influenced students' learning motivation in science classes.The research followed the Kemmis and McTaggart Classroom Action Research model, consisting of two cycles. Cycle I included four stages: planning, implementation, observation, and reflection. Cycle II was conducted based on the revisions resulting from the reflection in Cycle I and consisted of three stages: implementation, observation, and reflection. Before the implementation of the Skeleton Puppet learning media, students' understanding of the skeletal system and joints was relatively low. This was evident from the results of Cycle I, in which many students were categorized as Beginning to Develop (BD) or Not Yet Developed (NYD). After the implementation of the Skeleton Puppet learning media, students' understanding improved significantly. The results of Cycle II showed that the majority of students had reached the categories of Very Well Developed (VWD) and Developed as Expected (DAE).The findings indicate that the Skeleton Puppet learning media is effective in improving students' understanding because it provides a more concrete, engaging, and interactive learning experience. Therefore, the Skeleton Puppet innovation can serve as an effective science learning medium to enhance sixth-grade students' understanding of the human skeletal system and joints at SD Negeri 098 Pidoli.