<p>A method for producing p-isobutylstyrene which is characterized in that starting materials are inexpensive, the processes are easy to be done and products are highly pure. The method comprises the step of catalytically cracking 1,1-bis(p-isobutylphenyl)ethane at temperatures in the range of 200 to 650 DEG C in the presence of a protonic acid catalyst and/or a solid acid catalyst to produce p-isobutylstyrene and isobutylbenzene, and at least a portion of said isobutylbenzene is recycled to produce said 1,1-bis(p-isobutylphenyl)ethane by reaction with acetaldehyde in the presence of sulfuric acid.</p>