Abstract: Gas holdup and mass transfer of a reversed flow jet loop reactor in gas liquid solid three phase with non Newtonian fluids were examined experimentally. The influence of gas flow rate, liquid flow rate, draft tube to the reactor diameter, solid volume fraction, CMC solution concentration and its rheological property on gas holdup and volumetric mass transfer coefficient were discussed. It was observed that gas holdup and volumetric mass transfer coefficient increased with increasing gas flow rate and that liquid flow rate had little infuence on gas holdup and a little influence on volumetric mass transfer coefficient. It was also found that the optimum draft tube to reactor diameter ratio was in the range of 0.4 to 0.5, and the optimum solid volume fraction was about 3% under the experimental condition. Empirical corrections are presented for the gas holdup and volumetric mass transfer coefficient, which may be useful in the design of the reactor.