Abstract: Though digital pens facilitate artists,converting the sketchy line drawing into clean ones by artists’manual redrawing is time-consuming,which reduces their creation efficiency a lot.In this paper,we made use of drawing orders,upgraded the simplification model from the existed spatial relationship to temporal relationship and stroke modification relationship.We thus propose a double-level stroke simplification method in this paper.Our method first clusters all strokes locally and dynamically based on their drawing orders and spatial relationship,using the orders and positions that are recorded in the drawing stages;and secondly,it analyzes the drawing modification relationship based on a global modification graph,which allows it to better parse the artists’drawing intention.Our experiments demonstrate that,the proposed double-level stroke simplification method with the combination of local and global stroke analysis is able to simplify complex line sketches,and comparisons with the-state-of-the-art methods show the robustness and efficiency of our method.