Abstract :
The problem in this research is that there are many learners who after studying mathematics, unable to understand a mathematical concept even in the simplest much misunderstood concept that mathematics is regarded as difficult and hard science. Though understanding of the concept is the most important part in learning mathematics for mathematics courses emphasize the concept. The purpose of this study was to determine the ability of understanding of learners in understanding the concept mapping. The benefits to be gained from this research is that the organizers of the formal educational institutions as students can determine the ability of each learner in understanding the concept of mapping and can be used as a reference for future research. This study uses a qualitative descriptive study subjects were students of class VIII Semester 1 SMPK St. Theresia "Lumped" Kupang. As the selected data source class VIII F. From these data sources have been nine students as informants. Data was collected through observation, tests and interviews. The data analysis technique used is data reduction, data presentation and conclusion. The results showed that in the understanding of the concept mapping as measured by the seven indicators of understanding the concept well known that the study subjects who belong to the top, middle class, and lower group no one understands the concept mapping memyeluruh although the ability of each subject of study can be quite good but still there are errors - errors in understanding the concept mapping. Based on the research results suggested that the school continues to strive to develop the abilities of each student for the creation of man - Indonesian man who has a powerful ability.