This report provides an introduction to the analysis of innovation systems as they relate to green growth. The discussion begins by reviewing the basic elements of innovation systems theory, and then describes in detail a method of analysis that can be used by green growth practitioners to diagnose the functioning of an innovation system and develop policy recommendations to improve it. The first step is selecting the level of analysis (national, regional, sectoral or technological). The identification of the appropriate level for a practitioner interested in green growth is not straightforward and the first section provides a brief description of the benefits and drawbacks of each approach. Once the level of analysis is chosen, the next step is to understand the structure of the innovation system through a mapping of its key elements. The second section describes this mapping, including the main building blocks of an innovation system and information that can be gathered to analyze them. The final step is assessing the functioning of the innovation system and developing recommendations to improve it. The third section provides guidance on how to make this assessment along four fundamental dimensions, namely (a) generating and sharing new knowledge; (b) facilitating access to markets; (c) providing access to financing; and (d) nurturing skills for innovation.