With several complete plant genomes currently available and with massive amounts of transcriptomic, proteomic, and metabolomic data being generated by plant scientists, one could assume that making sense of all this data is only a minor problem. However, it has been pointed out by many leading plant scientists that this is not the case and that developing appropriate modeling skills and tools may lack behind the technological progress that allows the data generation. In recent years, the plant science community became more and more aware of the importance of different kinds of analysis and modeling approaches, like metabolic flux analysis. Accordingly, in this book, contributions from different expert authors have been assembled to give a current view on plant metabolic networks, from the analysis of the molecular parts to approaches of mathematical modeling of plant metabolic networks at the cellular level. Other processes like gene regulation, cell signaling or models at the whole plant or ecosystem level certainly have their justification [1], but have been mostly excluded here to give cellular metabolism special attention.