Abstract: Model clone detection is a very important technology for software maintenance, software structure optimization, etc. The paper first summarized the definition of model clone. Next, the overall detection process for model clone was divided and discussed in detail. After that, two kinds of typical clone detection technologies for larg}scale model were introduced. Finally, the paper reviewed the stat}of-art of current model clone detection research and identified some open research issues and pointed out possible future research directions in model clone detection area.

Key words: Model-driven development, Model clone, Clone detection, Sub-graph isomorphism, Characteristic vector