Abstract: A selective hydrogenation catalyst for pyrolysis gasoline. The catalyst mainly consists of a support of &dgr;, &agr; mixed alumina covered by palladium and alkali metal and/or alkaline-earth metal which are distributed on the support surface, and the support has 0.5 to 09. ml/g of specific pore volume. 40 to 200 Å pores account for more than 85% of the total pore volume. The specific surface area is 70 to 140 m2/g, and &agr; crystal structure in the alumina support is 0.5 to 5% based on the weight percentage of &dgr;, &agr; mixed alumina support. The catalyst includes palladium in amount of 0.05 to 0.4 wt %, alkali metal and/or alkaline-earth metal in amount of 0.05 to 2.0 wt %.