In order to get primitive actions for animation production, this paper proposes a visualization and interactive segmentation method for 3D human motion sequences. Firstly, a new feature based on bone angles of human skeleton is used to represent the original motion data. Then a heuristic method is introduced to detect the candidate segmentation points on the feature sequence. Finally, a graphical user interface is created to visualize the candidate segmentation points and pick the precise segmentation points interactively. Experimental results show that this method can divide motion sequence into primitive actions more conveniently, efficiently and precisely.