摘要：Teachers play an important role in the world of education, including in the process of planning the learning activities. A meaningful learning will be able to provide a good effect on students’ thinking ability. One of the students’ thinking skills that can be empowered is the critical thinking. Critical thinking skills can help a person to face the challenges of a globalized world. This research aimed at revealing the effect of PBL learning model on the critical thinking skills of multiethnic students. The design of this research was quasi experimental in non-equivalent pretest-posttest control group design. This research was conducted on multiethnic students of class XI Science in July-December 2016, in Samarinda, Indonesia. The results of the data analysis showed that learning model had an effect on students’ critical thinking skills. PBL model had a mean score of students’ critical thinking skill 73.81% higher than that of the conventional learning. Ethnics had an effect on students' critical thinking skills. The mean score of students’ critical thinking skills of Javanese was 11.94% higher than that of the Kutai ethnic, and 13.17% higher than that of the Banjar ethnic.
