中文摘要：

随着中国创新活动日新月异的发展，专利质量的变化趋势越来越受到研究人员的关注。使用中国发明专利每年发明专利的授权率和存续期表征专利质量，并且对发明专利的存续期使用Cox-PH模型进行回归，并以此分析了中国专利质量的演变趋势。研究结果显示，中国发明专利在授权率和存续期方面与国外存在一定差距，但与其他学者不同的是，无论是整体还是细分行业领域，中国发明专利的授权率在1985-1992年期间持续下降，之后在1993--2000年段显著上升，2001—2013年期间再次显著上升后趋于稳定；存续期则在1985-1992年期间呈现缩短趋势，但缩短力度在减小，之后在1993—2011年均呈现逐年延长趋势。尤其中国的电子工程领域在存续期上进步速度显著快于国外，以上均可证明中国专利质量在逐年提高。

英文摘要：

With the rapid development of China＇s innovative activities, the change of the quality of patent is increasingly concerned by the scholars. In this paper, patent quality is represented by patent grant rate and duration time of the patent, and the evolution trend of China＇s patent quality is analyzed by using a model of Cox-PH regressing the duration time of patent. The results of the study show that, foreign patents are better in terms of patent grant rate and duration time of the patent, but some differences were found between our research results and others＇ regardless of the whole or breakdown of the field： the China＇s patent grant rate continued to decline from 1985 to 1992, after that, rose significantly until 2000, then rose again and tended to be stable in the period of 2001 to 2013. In the period of 1985 to 1992, the duration time of patent gradually shortened, but the speed was getting slower, after that it gradually getting longer until the year of 2011, especially in this period, the China＇s patent quality progresses faster than abroad in the field of Electronic Engineering. Finally the conclusion can be drawn that China＇s patent quality is improving year by year.