Mathematical Induction (MI) is a subject that mathematics students have known since senior high school. However, many students lack understanding about MI and still incorrectly prove propositions using this proof method, even though they are 4-year students. Hence, investigating factors that influence students' comprehension of MI is needed. This study is a qualitative study that aims to investigate and analyze factors that could be influenced how students comprehend MI. The data were obtained within 2 phases. Participants were asked to write down the proof of provingquestion in phase 1, and they were interviewed to deepen the information in phase 2. The evidence suggests that conceptual aspects have to be focused more using many different ways of teaching strategies than the procedural one. Some factors which influence students' comprehension of MI include content knowledge, the experience of proving a variety of problems, the strategy of teaching used by lecturers, the language of the textbook, and the ability to do some algebraic manipulation.