This study aims to determine the ability to understand the concept of fractions in grade VII students of SMP Kristen Kusu-Kusu Sereh Ambon. The type of research used is qualitative descriptive research. This research was carried out at SMP Kristen Kusu-Kusu Sereh Ambon, with the data source being class VII-1 students totaling 20 students, and the research subjects selected to be interviewed were three students. Researchers describe students' ability to understand fractional concepts by looking at the results of student answers and interviews. The results of this student's test refer to the question instructions and the student's accuracy in answering. The accuracy of the student's answers is adjusted to the assessment criteria for the test questions and the scoring criteria for the ability to understand fractional concepts with four indicators, namely indicators of the ability to provide examples and non-examples, indicators of the ability to present concepts in various forms of mathematical representation, indicators of the ability to use, utilize and select specific procedures or operations and indicators of the ability to apply concepts or algorithms in problem-solving. Based on the results of the fractional concept comprehension ability test and student interviews, one student met three indicators of concept understanding ability, namely indicators of the ability to provide examples and non-examples, the ability to present concepts in various forms of mathematical representation, and the ability to apply concepts or algorithms in problem-solving, and two students who met one indicator of concept understanding ability, namely indicators of ability to provide an example and non-example.