: This research aims to describe students' mathematical critical thinking ability in solving circle problems according to indicators of critical thinking ability. The subjects of this study were class IX students of SMP Negeri 2 Pangkalan Kerinci consisting of twenty-one students based on low, medium, and high academic abilities. The instruments used in this study were question sheets to measure critical thinking skills which consist of four circle material questions with each indicator containing one question, and interview guidelines to find out the reasons for not achieving critical thinking skills indicators. The data analysis technique starts from collecting data on students' KBKM test results, student work results are grouped according to the achievement of each indicator, and the achievement of each indicator is analyzed to find out the causes of the non-achievement of these indicators. The results showed that students' critical thinking skills were low with an achievement percentage of 48%. Students with high abilities have been able to interpret problems and make analyzes but there are still students who are wrong in student calculations, students in the middle category have been able to interpret problems and analyze but for inference and evaluation have not been complete, students in the low category have not been able to interpret problems as well as analysis and evaluation to conclude a math problem.