It is generally accepted that photosynthesis, whereby solar is transformed into geobiochemical energy, is one of the most important processes in the bio sphere. When we realize that the human population, most of which is starving, wi I I double in 20-30 years, and that photosynthesis is in practice the only source (direct or indirect) of food not only for men, but for al I I iving beings, its im portance becomes even plainer. This fact was recognized from the outset of the International Biological Programme, when photosynthesis was selected as one of the principal problems to be concentrated on. The significance of the IBP in initiating a broader-based ap proach and worldwide collaboration need not be emphasized here; it is merely ne cessary to consider the rapid increase in the number of papers on photosynthesis since its inception. It is of fundamental importance for scientists working on photosynthesis to get information on what has been done in recent years in this discipl ine. Thus as complete as possible a bibl iography is badly needed. The complexity of this pro blem requires also that the progress of ecology, chemistry and physics, as far as they concern photosynthesis, be fol lowed. Such a bib I iography, covering at least the last ten years, wi I I be indispensable for final synthesis of the results of the IBP photosynthetic programme.