Critical thinking skills are competencies that must be trained in students because these skills are essential to compete in the life of the 21st century. The purpose of this study is to determine the level of critical thinking skills of students in biological material in Muhammadiyah High School throughout Palembang. This research is a qualitative descriptive study; the population and sample in this study were students of class XI IPA Muhammadiyah High School in Palembang. The research instrument used was a test of critical thinking skills as many as 20 multiple choice questions of semester XI biology material 1. The data obtained will be analyzed quantitatively. Quantitative analysis is used to analyze students' test results. The results showed the level of critical thinking skills of students in Muhammadiyah High Schools throughout Palembang City varied; the exceptionally high category was obtained at 1.85%, top category amounting to 14.5%, medium category 66.6%, low category 16.4% and category very low at 0.5%. The results of this study provide information on the profile of students 'critical thinking skills in Muhammadiyah High Schools throughout Palembang City with the highest moderate category so that teachers are expected to be able to design learning process activities that can empower students' critical thinking skills.