In this study, it was observed that hydrogen Productivity varied with stirrer speed, bead radius, input glucose concentration and dilution rate in a continuous stirred tank reactor in which immobilized R. rubrum KS-301 was used as a hydrogen-producing bacterium The mass transfer resistance due to cell immobilization was also studied. In order to estimate an effectiveness factor, Des of glucose was first obtained, which was subsequently represented by the correlation equation between Dos and Xb, As a result external mass transfer resistance could be neglected for stirrer speeds greater than 400rpn With bead radius increasing, the hydrogen productivity and internal effectiveness factor decreased. With input 91ucose concentration increasing, the hydrogen productivity and interval and external effectiveness factor increased. Although an Internal effectiveness factor was not affected, hydrogen productivity Increased with dilution rate increasing. An overall effectiveness factor remained nearly constant for the dilution rates investigate4 but increased with input 91ucose concentration increasing.