Laboratory-scale systems for bioconversion of CO2 to biofuels, H-2 and ethanol, have been developed in an attempt to present data for baseline evaluation of a resource recycling technology utilizing biomass of cyanobacteria. The procedure employs cultivation in the light of photolithotroph Synechococcus leopoliensis, onset, by shift into anaerobic dark, of hydrogenase-mediated H-2 formation reaction, and conversion of biomass waste into ethanol. Cyclic turnover of carbon by harnessing photosynthesis was successfully demonstrated by the experiment, but the research for a large-scale fuel production is still in its preliminary stage.