中文摘要：

以重庆维普期刊全文数据库中2000～2009年发表于生物技术领域的合著论文作者信息统计数据为数据源,从省级层面运用UCINET和ArcGIS软件分析知识网络的空间结构特征及其演化规律。近十年来生物技术知识网络经历了由萌芽阶段向扩张阶段和成熟阶段转变的过程,知识的扩散方式由接触扩散为主向等级扩散为主转变,知识交流的密集区在空间上相应地经历了由分散到集中到再分散过程,网络节点间地理临近和组织临近的相互作用共同推动着网络空间结构的演化。研究表明：从缩短知识主体的社会距离和优化创新资源的空间配置两个角度,对我国国家创新系统推进生物技术发展提出建议,以提高科技投入产出效率和空间配置效率。

英文摘要：

Knowledge network is a kind of inter-connected network that is born in the process of diffusion and communication of knowledge by the actors who create,transfer,absorb and apply knowledge,such as enterprises,universities,organizations and institutions.Network structures may exert influence on the actors and regions involved,and the potential for successful knowledge absorption and learning may be partly determined by network positions.Up to present,there are no researches about the evolution of spatial structure of knowledge network in China.In recent years,the evolutionary economic geography in Europe and USA begins to explore the spatial structure and evolution of knowledge networks from the geographical angle.But because of language and cultural barriers,the western research focused more on international knowledge flows and connections about knowledge networks in China,while the evolution of Chinese domestic knowledge networks were rarely involved.Purposes of this paper are： 1） to establish the estimation model to analyze the formation mechanism of spatial patterns of knowledge network,and to reveal the dynamic mechanism of its evolution;2） to provide some advice to the government for policy making of national innovation system.This paper takes statistical data of the papers published in cooperation about the biotechnology in the database of Chinese Scientific and Technical Journals（Journal of Chongqing VIP） from 2000 to 2009 as data source.Based on the theory and methods of social network analysis in New Economic Sociology,it uses UCINET and ArcGIS to analyze the spatial structure and the evolution of knowledge network of biotechnology at provincial level in China.In recent 10 years,the knowledge network developed in three phases： infant stage,expansion stage and maturity stage.Accordingly,the major pattern of knowledge diffusion in the network changed from contagious diffusion to hierarchical diffusion.The spatial high-density of knowledge connections also changed from decentralization to concent