Abstrak This study aims at describing and analizing the students’ mathematics problem solving ability based on Contextual Teaching and Learning (CTL) through REACT approach. The method of this study is quasi experiment, and the samples are three junior secondary schools (SMP) that consist of higher, middle, and lower ranks of students at SMP in Bandung City. This study was carried out in two eighth grade classes selected by a random cluster sampling technique. The finding shows that the mathematics problem solving in REACT classes is better than that in conventional classes of the higher ranking school. But the achievements based on prior mathematics ability of the lower ranking SMP of the REACT class and conventional class is slightly different. Only at the lower ranking SMP, the mathematics reasoning ability of conventional class is higher than the REACT class. Most of the students underwent difficulties in solving mathematics essay test that aimed at measuring their reasoning ability. REACT weakness that focus on giving chance to construct new knowledge based on students’ ability is the time management on each class activity because of the limited school schedule.