The aim of the study was to examine the improvement of basic science process skills among second graders in science learning through an inquiry-based approach. The participants were 23 students from a second graders class. Participants were with the age around seven years old. The 5E model of inquiry-based approach was used to teach science. Mixed method approach used in the study. The qualitative data were collected through classroom observation, teacher interviews, and students' works. The quantitative data were collected from performance tests measured by using a rating scale instrument. The improvement of basic science process skills were examined through descriptive statistic and t-tests. The study showed that the basic science process skills improved after the intervention of learning. The study also revealed the factors contributed to the inquiry-based approach of science learning to develop the basic science process skills, such as the use of worksheets, singing a song, and the interactions with both peers and teacher.