在专利数量快速增长的背景下，由大量专利形成的专利群成为专利领域的新现象，由于类似生长茂盛的灌木丛，被形象地称为专利丛林。面对海量的专利数据，如何测度专利丛林和分析演进过程是亟待研究的问题。通过分析专利丛林的生成机制，基于有效专利构建专利丛林的测度指标，采用层次聚类分析方法，定量划分专利丛林的演进阶段。运用以上构建的分析方法，选择喷墨打印技术为研究样本，基于长周期的时间序列数据，对专利丛林进行分析测度并揭示其演进过程。

With the rapid increase of patents, patent clusters formed by a large number of patents are becoming a new phenomenon in the patent field. Patent clusters are also referred to as patent thickets, because they are similar to lush thickets. It has become an urgent task to measure patent thickets and analyze the evolution from the massive data. The generation mechanism of patent thickets has been analyzed in this paper. The measurement index of the patent thicket is developed based on valid patents. The hierarchical cluster analysis is employed to classify the evolution periods of patent thickets. Taking inkjet printing technology as the research sample, the methods are employed to measure the patent thickets and analyze the evolution with the data of long-term time series.