To provide an asphalt-modifying material which exhibits excellent solubility in asphalt, surely ensures firm adhesion to an aggregate and strongly suppresses phase separation of the modified asphalt when jointly used with a rubber or a thermoplastic elastomer for modifying asphalt, a method for manufacturing the asphalt-modifying material, and a method for modifying asphalt using the asphalt-modifying material.

The asphalt-modifying material comprises as essential ingredients a (meth)acrylic polymer and an oil, where the (meth)acrylic polymer is dissolved or dispersed in the oil and the kinematic viscosity at 100°C measured according to the specification of JIS K 2283 is at least 15 mm2/sec.