Abstract: This paper constructs an analysis framework of time-filed, and analyzes the distribution structure evolution of the U.S. technological innovation base on the patent data of 1963-2008. Firstly, the result shows that the distribution structure of the U.S. technological innovation fields gradually concentrates on just a few technology fields from 1963 to 2008 with the approach of rank-frequency and concentration ratio. In recent years, it always maintains in the “5-55” pattern. That is to say, the patents of top 5 technology fields which have the most utility patents account for about 55% of all the utility patents in the U.S.. Then, according to the total patents and the relative growth rate of each technology innovation field, we divide them into 4 development patterns which are leading-growth, emerging-growth, leading-maturity and germinative (recession)-sluggish. The result of CV (coefficient of variation) indicates that leading-growth and emerging-growth patterns develop unstably and the leading-maturity pattern develops relatively stably.

摘要： 本文建立“时间-领域”分析框架，运用1963-2008年专利产出数据分析美国国家技术创新领域的结构演变。首先，运用排序-频度和集中度方法分析技术创新领域分布结构演变，结果显示美国国家技术创新领域分布逐步向少数技术领域集中，近年来维持“5-55”的基本格局，即排序前5位的技术领域发明专利授权量约占美国所有发明专利授权量的55%左右；其次，根据专利总量和相对增长率等指标分析了技术创新领域时间分布结构，将技术领域划为主导-成长型、新兴-成长型、主导-成熟型、萌芽（衰退）-滞长型四种发展模式，由各技术领域的变异系数特征发现主导-成长型和新兴-成长型的技术领域发展不稳定，主导-成熟型技术领域发展相对稳定。

关键词: 技术创新, 分布结构, 演变, 专利, 美国, technological innovation, distribution structure, evolution, patent, the U.S.