The implementation of Higher Order Thinking Skills in teaching and learning mathematics was very important to change the community's stigma on mathematical difficulties. HOTS can also attract students to foster their interest in mathematics. The purpose of this study is to examine the ability of mathematics teachers to develop HOTS-oriented learning. This research is phenomenological research with a qualitative approach involving a mathematics teacher in Subang Regency. The data analysis stage was carried out by observation to observe HOTS-oriented learning and interviews to confirm the findings in each process. The results showed the teacher had tried to do Mathematics oriented to HOTS despite finding some obstacles. Teachers should exchange knowledge and pedagogical knowledge with other teachers and then be consistent in continuing HOTS-oriented learning so that students are accustomed to HOTS.