Critical thinking is one of the objectives of implementing an in-depth curriculum, but the critical thinking ability of students at SMAN 4 Tana Toraja is still not optimal because students are less able to provide explanations such as analyzing mathematical problems. This study aims to analyze the mathematical critical thinking ability of class X students of SMAN 4 Tana Toraja on exponential material. The method used in this study is descriptive qualitative. Data collection techniques used are interviews and test questions. The main instrument is the researcher himself and the supporting instrument used is a description of one problem. The subjects of this study were five class X students of SMAN 4 Tana Toraja who were selected using a purposive sampling technique. Thus, it can be concluded that the mathematical critical thinking ability of class X students of SMAN 4 Tana Toraja on exponential material is still low. This is evident from the results of interviews that there are still many students who still do not understand the steps that must be taken to answer questions correctly and precisely.