To provide a prepreg which can exhibit the characteristics of high thermal resistance and low thermal expansion, and a copper-clad laminate with no poor appearance.

The prepreg is prepared by coating a base material with a resinous varnish followed by drying, the resinous varnish comprising, as an essential component, a slurry formed by mixing and heat-reacting (A) an epoxy resin having three or more epoxy groups in the molecule, (B) a phenolic resin curing agent having three or more phenolic hydroxyl groups in the molecule, and (C) a spherical fused silica having an average particle size of 2 μm or less, a coupling agent and a solvent.