Abstract: Based on the surface free energy theory, firstly, the contact angel between asphalt, aggregate and known reagent was measured, then the adhesion and peeling work and water stability index ER of asphalt-aggregate composites were calculated according to relative formulas, followed by the analyse of the change of adhesion abilities of asphalt and aggregate before and after aging. The results show that the adhesion and peeling process of asphalt-aggregate composite release heat energy to external and are spontaneous. For the composite of same asphalt and different aggregate, the rank of adhesion and resist water damage ability from strong to weak is asphalt-limestone > asphalt-basalt > asphalt-granite, and for the composite of different asphalt and same aggregate, the rank is composite modified asphalt(CM)-aggregate > rubber crumb modified asphalt(CRM)-aggregate > styrene-butadiene-styrene modified asphalt(SBSM)-aggregate. After aging, the adhesion and resist water damage ability of asphalt-aggregate composite present a decline trend and the pressure aging vessel(PAV) is more clear than rolling thin-film oven test(RTFOT), but aging process does not change the compatibility of asphalt-aggregate composite; By analyzing the SEM image of three modified asphalt after aging, it can be discovered that the interface adhesion properties between asphalt and aggregate has been changed, which results in adhesion ability decreases of asphalt and aggregate.