The alkylation reaction of benzene with 1-dodecene was investigated in a liquid-solid circulating fluidized bed reactor (LSCFBR) using HY zeolite as catalyst. The conversion of 1-dodecene, the apparent reaction rate constant, the activity of catalyst and the product distribution in the LSCFBR were analysed and compared with the values obtained using a stirred tank batch reactor (STBR).