The development of high-order thinking skill of students is one of the keys to success in adapting to changing times and entering the world of technology. This ability should be developed since students in elementary school. The research aims to improve students’ high order thinking skills through integrative thematic-based science learning with scientific approaches. The research was conducted at one of the elementary schools in Ambon, East Indonesia used the quasi-experimental method with pre-post-equivalent control group designs. Data collection techniques are carried out through high-order thinking tests with indicators determining aspects, making decisions, making ideas, reasoning, and communicating. Furthermore, the data were analyzed using an independent sample t-test with a significance level of 0.05. The results showed that the average N-gain value of the experimental group was 0.7427 higher than the control group 0.4338. So it can be concluded that thematic integrative science-based learning with a scientific approach can improve students’ high order thinking skills in elementary schools.