herelatiomhipbetween compaction energy and key sieve size passing percentage of 27 experi-ment gradings ale analyzed for SAC一20.ne passing percentage of 1.18ram sieve size has the greatestimpactoncompaction energy，thenhas thepassing percentageof 0.075ram sieve size，∞the conclusionthat fineaggregate gradingand itscontent(includingthe filler)hasgreat impact on compaction energy Canbeget.,111e average compaction numberdecreases with the increasing of thepassing percentage of 1.18mmand O.6mm sieve size.Wh∞the two passing percentage of the sieve size above increases into the restrictedzone of Superpave for the corresponding fine aggregate grading，the compaction number will be less，andthe mixture will becompactedH10l'eeasily，thiswill reduce the rut—resistanceperformance of mixture.Sothe restricted zone has definite rationality，and the passing percentage of key sieve size for fme aggregateshould be under the restricted zone.