F1- and V1-ATPases are unique rotary molecular motors which convert the chemical free energy of ATP hydrolysis into mechanical work of rotation. The rotary dynamics of F1-ATPase has been extensively studied by structural and single-molecule analyses, which revealed the detailed chemo-mechanical coupling scheme between chemical reactions and rotation and the 100% free-energy transduction efficiency. In contrast, knowledge on the structure and rotation dynamics of V1-ATPase has been limited. However, recent high-resolution structural studies and single-molecule studies have begun to clarify the rotation mechanism of V1-ATPase. To fully understand the rotation mechanism of rotary ATPases, it is essential to highlight the differences and similarities in the rotation mechanism between F1-ATPase and V1-ATPase and reveal rotary statistics of rotary ATPases. Here, I will introduce recent advances in our knowledge of rotation mechanism of these rotary ATPases revealed from single-molecule approaches.