For the treatment of including refractory material in wastewater, an airlift ultrasonic reactor was proposed. The reactor was a bubble column with a draft tube and an ultrasonic oscillator attached at the column bottom. The gas was sparged into the draft tube or into the annulus between column and draft tube. The gas velocity was changed and the apparent decomposition reaction rate constant of tetraphenylporhyrine tetrasulfonic acid was measured. Regardless of the mode of sparging gas, the apparent reaction rate constant increased with increasing gas velocity. To examine the effects of liquid and gas velocities on the apparent reaction rate constant in the airlift ultrasonic reactor, a tubular reactor with an ultrasonic oscillator was used. In the tubular reactor, the liquid and gas velocities were independently controlled, and the apparent reaction rate constant was measured. The apparent reaction rate constant increased with increasing liquid velocity or with increasing gas holdup. The effects of liquid velocity and gas holdup were expressed by experimental equations. For the apparent reaction rate constants in airlift ultrasonic reactor, the results calculated from experimental equations agreed well with the measured data within an error of +/- 30%.