中文摘要：

完善区域创新网络和提高知识溢出效应是提升区域创新能力的关键。文章以环长株潭城市群知识溢出为研究对象，采用社会网络分析理论和Gephi软件方法，利用2005-2014年工程机械类发明专利的合作申请和引用数据构建创新网络，从空间、产业和组织三个维度分析其创新网络结构特征和演变规律。研究发现：第一，环长株潭城市群创新网络从无到有，处于初级阶段，创新产出和空间溢出水平较低；第二，创新网络在空间上呈现以长沙为核心，其他节点围绕长沙形成“核心一边缘”的分布模式；第三，知识和技术溢出集中在工程机械及相关产业，表现出以MAR溢出为主，正处于从MAR溢出向Jacobs溢出过渡的阶段；第四，形成以大学和大型科技企业为核心节点的产学研关系网络，但与政府、金融和中介机构关系不够紧密。创新网络演化受经济实力、吸收能力、交通网络、组织差异和社会文化关系等多因素驱动，知识溢出并不是单纯呈距离衰减趋势。最后提出完善创新网络的对策措施。

英文摘要：

It is the key to enhance the regional innovation capability through improving the innovation network and the effect of knowledge spillover. Based on social network analysis theories and Gephi methods, engineering mechanical invention patent applica- tion and patent citations from 2005 to 2014, we constructed the innovation networks from the three dimensions of space, industry and organization to study the structure characteristics and evolution law of innovation network of the ring of Cbangsha - Zhuzhou - Xiangtan urban agglomeration. Our research findings are as follows ： First, the innovation network of the ring of Changsha - Zhuzhou - Xiangtan urban agglomeration has grown out of nothing and still in the primary state, so the level of innovation output and spatial spillover is low. Second, the innovative network centers around Changsha spatially, with the other nodes around it and forming the ＂ core -edge＂ dis- tribution patterns. Third, Knowledge and technology spillover in engineering machinery and related industries feature in MAR overflow and are in the transition phase from MAR to Jacobs overflow. Fourth, it forms an industry - university - research cooperation network, with top universities and large technology enterprises as its core node, but only loose contact with government, financial and intermedi-ary institutions. There are economic power, absorptive capacity, transportation network, organizational differences, social and cultural relations, and other factors to drive the evolution of innovation network. Therefore, knowledge spillover is not only the trend of distance attenuation. Finally, it puts forward the and suggestions to improve the innovation network.