The SBA-15 supported 12-phosphotungstic acid catalysts were prepared and measured in the alkylation of benzene with 1-dodecene at the atmospheric batch reactor. It is found that the catalysts exhibit much higher catalytic activity, selectivity and stability than HY zeolite in this reaction at the reaction temperature of 80degreesC, with the 1-dodecene conversion of nearly 90%, 2-phenyldodecane selectivity of nearly 40%, and monoalkylbenzene selectivity of 100%.