Reasoning ability encourages students to think logically, so it is a very important part in learning process. This qualitative descriptive study aims to determine the mathematical reasoning ability of Junior High School students in solving non-routine problems of the two-variable linear equation systems material. The subjects were 6 students of class VIII.7 SMP Negeri 17 Palembang. Due to Covid-19, the research was conducted online using test and interviews, and analyzed descriptively. The results showed that of the 7 indicators of mathematical reasoning ability used, high-capable subjects fulfill almost all indicators. Indicators are not fulfilled in namely posing an assumption, perform mathematical manipulation, draw conclusions, compile evidence, provide reasons or evidence for the correctness of the solution to problem 1 and find patterns or properties of mathematical phenomena that will be generalized to problem 2. Indicators that are not fulfilled in medium-capable are perform mathematical manipulation, draw conclusions, compile evidence, provide reasons or evidence for the correctness of the solution and find patterns or properties of mathematical phenomena that will be generalized to problem 2. Students with low-capable still not dominant and only permit indicators to present oral, written, picture and diagram math statement and draw conclusions from those statements.