Batch culture hydrogen production by the purple non-sulfur phototrophic bacteria Rhodoseudomonas palustris CQK-01 was experimentally investigated in a novel gas sparging photobioreactor. The effects of sparging frequency on the growth and hydrogen production performance of Rhodoseudomonas palustris CQK-01 are discussed. The experimental results showed that sparging Ar gas into the reactor effectively reduced hydrogen concentration in the culture and hence weakened the product feedback inhibition, resulting in enhancement of hydrogen production performance. The gas sparging frequency was found to be an important factor for bacterial growth and hydrogen production by photosynthetic bacteria(PSB), and the optimum hydrogen production performance of the bioreactor was achieved under gas sparging with an interval of 3 h. The total hydrogen production, light conversion efficiency, hydrogen yield, average substrate consumption rate and average hydrogen production rate were 33.25 mmol, 18.46%, 1.79 mol (H2)/mol (glucose), 0.28 mmol L-1 h-1 and 0.50 mmol L-1 h-1, respectively.