Abstract: The chemical composition of by-product from terpineol production was analyzed by GC-MS, and 22components were identified. The main components are limonene,isoterpinolene,α-pinene and eucalyptol etc. Reaction of terpineol production by-product which was catalyzed with SO42-/TiO2-ZrO2solid superacid were studied. The effects of conditions for preparation of SO42-/TiO2-ZrO2catalysts, such as ratio of Ti to Zr, calcination temperature, reaction temperature, reaction time, catalyst dosage, on its catalytic activity was investigated. Furthermore, the effect of storage time of the cataIysts on the reaction was discussed, and the experiments of catalyst repeat use were carried out. The products of reaction were identified by GC-MS. In the reaction, the main product was p-cymene, and the by-products were terpinolene and α-terpinene, as well. The results showed that the optimum conditions for the preparation of SO42-/TiO2-ZrO2catalysts were the ratio of Ti to Zr 3mol/mol, and calcinations temperature 650℃. At these conditions, the main factors affecting the reaction were investigated in the work. The optimum conditions for by-product reaction from terpineol production were as follows: reaction time 6h, reaction temperature 130℃, and catalyst dosage 3%. Under these conditions, the content of p-cymene was 60. 60%.