In this study, we investigated the immobilization of loofa sponge as a carrier for plant cells using a novel immobilization reactor, namely, a two-way bubble circular (TBC) reactor, for analyzing the effects of medium flow pattern. A TBC reactor, in which two-way circular flow prevailed and was controlled by bubble flow and sparger adjustment, was developed as a suitable system for plant cell immobilization using loofa sponge. In this system, relatively small aggregates of cultured plant cells could be immobilized, and the entrapped cells grew quickly, avoiding cell leakage from the sponge throughout 31 days of incubation. The optimum immobilization conditions and immobilization mechanism in this system were investigated using Coffea arabica cells as a model cell line. By changing the flow direction of culture medium in the circular reactor periodically between downflow and up-flow, cell immobilization efficiency of the loofa sponge was improved as compared with reactors using one-directional flows, The specific respiration activity of cells immobilized in loofa sponge was also studied, Uniform distribution of cell density and specific respiration activity were obtained along the axial direction of the loofa sponge. In the same reactor system, loofa sponge exhibited high immobilized cell concentration and specific respiration activity not less than those of polyurethane foam.