This paper presents a part of a French-Sino PhD project. It investigates mathematics teachers’ practices, while using 3D dynamic geometry environments (DGE), for coordinating students’ empirical perception and logical reasoning, and the teachers’ justification for their coordination behavior. Adopting a qualitative approach in a multiple-case study, we select two teachers both in France and in China and develop a framework to analyze teachers’ coordination behavior in lessons with 3D DGEs. The analysis reveals several patterns of coordination behavior, which are unevenly distributed among the four teachers’ cases. Subsequently, the teachers’ justifications are identified and contrasted. The findings illustrate how teachers’ coordination patterns could be influenced by institutional, pedagogical, material and temporal factors. Finally, some implications for teacher education are drawn, along with a cross-cultural perspective for future research on 3D geometry teaching with technology.