Based on the molecular dimensions for typical aromatics and sulfur-containing compounds in diesel oil , shape selection and hydrogen spillover, a support was designed for sulfur-tolerant catalysts to reduce aromatics at the second stage. For the purpose a novel molecular sieve composite Y was prepared and the as-synthesized samples characterized with a variety of techniques. The results indicate that this composite is different from the mechanical mixture of MCM-41 and NaY under the same condition. It possesses both a modal mesopore system and a microporous structure of zeolite Y. Moreover this catalyst presents, when loaded with PdPt/H(MCM-41/Y), a promising tolerance to sulfur and a handsome ability of pyrene hydrogenation.