This study aimed to describe the conceptual thinking process of students in solving geometry problems in terms of the temperament differences including five competencies, namely uses basic rules, sees patterns, applies concepts, clarifies situations, and creates new concepts. This research was a descriptive research with qualitative approach. The subjects consisted of four female students with high and equivalent mathematics abilities in the ninth grade of the basic level of formal education in Salatiga, Indonesia, equivalent to junior high school, namely students with sanguine, choleric, melancholic, and phlegmatic temperaments. Data collection techniques were job-based interviews. The results showed that student with sanguine temperament did not master the two competences of conceptual thinking process that were clarifies conditions and creates new concepts, student with choleric temperament mastered the whole competences of conceptual thinking process, student with melancholic temperament did not master a competence of conceptual thinking process that was created new concepts, and student with phlegmatic temperament did not master a competence of conceptual thinking process that was created new concepts. Some students had mastered the competence of conceptual thinking well because it was indicated by the master of the problem solving indicator used. However, they did not understand the benefits of the conceptual thinking process in solving the problem itself. Regarding student difficulties, students admitted most often failed in developing the problem. Further research needs to be done with reviews of other aspects because the success of student learning is not only influenced by the temperament aspect.