中文摘要：

共词网络是科学知识网络的有机组成部分，本文总结了针对学科的共词网络研究的方法、程序和图谱绘制流程，采集了1900～2012年图书馆与情报学领域国际期刊的数据，将其中的高频关键词利用学科共词网络图谱展示出来。在剖析网络结构特征的基础上，得到7个子网络，其主题分别对应于知识管理、图书馆、信息检索、信息技术、文献计量、信息政策、电子商务等，7个图书馆与情报学领域的热点主题基本都是图书馆与情报学目前研究的热点主题。本文还设计了主题－主题共现矩阵，使用了以主题本身为节点的主题层级的网络图谱揭示了这七个主题之间的关联，分析了七大热点主题的核心关键词词频随着时间变化的演化图谱，最后着重对学科共词网络的研究方法的局限性进行了反思和讨论。

英文摘要：

Co-word network is one important part of scientific knowledge networks. In this paper all keywords from international journals of Library and Information Science category from 1990 to 2012 was collected and represented by high- frequency keywords and their relationship in visual social networks. After been summarized by the common co-word network analysis methods, procedures and drawing processes, seven emerged sub-networks in the whole network were corresponded to seven hot topics in Library and Information Science respectively, including Knowledge Management, Libraries, Information Retrieval, Information Technology, Bibliometrics, Information Policy, and E-commerce. In order to reveal the relationship and the corresponding strength among these seven sub-networks, a topic-topic input matrix was constructed to generate the topic network in which their nodes were referred to the hot topic. The core keywords were exacted from the seven hot topics with their evolution of frequency over time was displayed in the graph. At last some of the disadvantages in method of co-word network were summarized and highlighted in this paper.