This descriptive study aims to describe the mathematical reasoning ability of class XI students of SMKN 3 Sungai Penuh City in solving mathematical problems on the matrix. Collecting data on students' mathematical reasoning abilities using test and documentation techniques. The test instrument used is a description of 7 items about mathematical reasoning abilities. The data collected were analyzed qualitatively by reducing, presenting, and drawing conclusions. The subjects of this study were 20 students of class XI Clothing 3 SMK 3 Sungai Penuh City. The results showed that the mathematical reasoning ability qualification of 50% of students was categorized as very good, able to estimate answers and the solution process, compiling direct proofs, and being able to draw logical conclusions in accordance with reasoning on solving matrix problems. Furthermore, thes good category was achieved by 25% of students, able to estimate the answers and the solution process but were incomplete, compiling direct proofs, and drawing logical conclusions from solving matrix problems. Then there are 25% of students who reach the category of being quite able to estimate answers and the solution process but are not correct and incomplete, unable to complete direct evidence, and cannot draw logical conclusions because the completion is incomplete. Furthermore, there are no students with mathematical reasoning abilities in the less and very less categories.
