Development and innovation of clean technologies have been an important proven reliability of realizing the global goal for mitigation of climate change and progress of emission reduction. Both IPCC Fifth Assessment Synthesis Report and IPCC Fourth Assessment Synthesis Report highlighted the importance of innovation of mitigation technologies for coping with the climate change issues and provided categories and guides for a collection of mitigation technologies as well. The guided technologies covered a wide range of industries from producer side to consumer side. More and more countries in the world engage in promoting and accelerating the innovation of mitigation technologies especially China,which is the biggest emitter of exhaust fumes and this also goes to the list of responsibilities which countries and regions should shoulder to cope with the international issue of climate change. However,special attentions should also be paid to precisely targeted technologies when promoting the overall innovation of mitigation technologies,which basically relies on a comprehensive summary on innovation choices and preferences. It is of great significance for the development trends and R&D strategy of clean technology to explore the R&D choice of the agents and summarize its evolution rule. Meanwhile,more and more scholar are increasingly interested in studying the evolution of innovations of mitigation technologies worldwide. These researches have offered some insights how mitigation technologies emerge and the potential relations between different technologies. This study utilizes a data set of patent samples matched by the Green Patent Inventory and world invention patents data from 2009 to 2014,covering data tags of application number,issue number,title,abstract,classification number,applicant,inventor etc. The Green Patent Inventory also includes seven major categories of green technologies with 1138 sub - categories,which can provide a manifest list of either mitigation technologies or adaptation technologies by matching with the patent data. Based on the data set,this study builds the clean technology innovation network depending on the sequential relations among patents. On contrary to the existing literature,the model is extended to not only include the citation connection but also the evolutionary and temporal pattern. By taking the time when applicants of each patent applied for patents into consideration,the evolutionary pattern reveals the facts that how innovation of mitigation technologies shift along the technological chain vertically and how technologies in different disciplines interact with each other horizontally. From the perspective of network analyses and minimum spanning tree algorithm,this study analyzes the structural features,important vertices of technologies and critical technical path in the network and presents both of the marco - and micro - observations.