Abstract:Patent strength is one of the important factors, which affecting the ability of the national science and technology innovation competition. The comprehensive evaluation of patent strength enables the national to grasp the development trend of science and technology innovation to a certain extent, which making the national take effective measures to improve the level of national patent strength and science and technology innovation. On the basis of this, it established the comprehensive evaluation index system for patent strength based on the relevant research of patent evaluation index. Secondly, it used method combines entropy weight and grey correlation analysis to determine the combinational weight and it made the comprehensive evaluation for the evaluation of patent strength. Finally, the evaluation of index system have been tested by analyzing the empirical application case, which not only verifying the practicality of our national patent strength, but also justifying the rationality of the evaluation index.