A turbine blade reactor (TBR) was employed to cultivate rice calli immobilized in polyurethane foam as a support. In the bioreactor, rice callus could be immobilized quickly in a 3 mm cube of the support, and then attached to the stainless mesh cylinder set at the center of the bioreactor. For improving the immobilization ratio of rice callus in the bioreactor, the optimum support volume and bioreactor operation and modification were investigated. The support volume had a pronounced effect on the immobilization ratio of rice callus, and the maximum volume was found to be 60 ml. By repeating a periodic operation three times (agitating at 300 rpm for 5 min and then 50 rpm for 2 min, and then 200 rpm of constant agitation speed during the remaining time), rice calli were uniformly entrapped in almost all supports and the immobilization ratio was improved as compared with that using a constant bioreactor operation at 200 rpm. When the inoculum concentration of rice callus was increased, the callus concentration after 7-day culture increased, but the immobilization ratio decreased. To improve the immobilization efficiency further at high cell concentration, the TBR was modified by setting an air sparger inside the stainless mesh cylinder. In the modified TBR, floating of the support by attached air bubbles was avoided, and the immobilization ratio increased further and reached 86.3% when we increased the support volume to 90 ml under the periodic bioreactor operation on a daily basis. The regeneration frequency of immobilized callus was increased by periodic operation and modification of the bioreactor.