Abstract: Line art generation is a key step in computer-aided drawing.The results generated by current automatic tools from draft images can not meet the requirements in practical applications.The interactive process using “pen”or “pencil”tools is boring and time-consuming.To solve these problems, this paper proposes a semi-automatic approach for line art generation from a digitalized draft image.Firstly an initial line art is generated by an automatic process including strokes extraction and vectorization.Then the final line art is obtained via intuitive and smart users'interactions based on line-fragments.User studies show that the proposed approach can generate satisfied line art images that are similar to those by manual methods.It greatly reduces manual operations and processing time and improves the overall process of personal computer-aided drawing.