Biohydrogen production with the light-harvesting function of grana from spirulina by use of three-component system consisting of NADH, methylviologen (MV2+) and colloidal platinum was investigated. The decay rate of chlorophyll included in grana was suppressed by addition of NADH and little degradation was observed in 120 min irradiation. The biohydrogen production system was developed using the light-harvesting function of grana and platinum colloid in the presence of NADH and MV2+ and the amount of hydrogen produced was estimated to be 0.14 mu mol after 4 h irradiation. (c) 2005 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.