Objectives To investigate the feasibility of coupling carbonyl cyanide m-chlorophenylhydrazone-regulated photohydrogen production by Tetraselmis subcordiformis in a photobioreactor to an alkaline fuel cell (AFC). Results H-2 evolution kinetics in the AFC integrated process was characterized. The duration of H-2 evolution was prolonged and its yield was improved about 1.5-fold (to 78 +/- A 5 ml l(-1)) compared with that of the process without AFC. Improved H-2 yield was possibly caused by removal of H-2 feedback inhibition by H-2 consumption in situ. Decreases in the H-2 production rate correlated with the gradual deactivation of PSII and hydrogenase activities. The H-2 yield was closely associated with catabolism of starch and protein. Conclusion A marine green algal CO2-supplemented culture integrated with in situ H-2-consumption by an AFC system was developed as a viable protocol for the H-2 production.