To provide a reinforcing method for a permeable asphalt paving layer capable of increasing adhesion of aggregates with one another in the permeable asphalt paving layer by a simple method.

Gas containing oxygen is blown on the permeable asphalt paving layer constructed by a permeable asphalt paving asphalt mixture, the gas containing oxygen is infiltrated into the paving layer to accelerate oxidation reaction of asphalt, and stability of the permeable asphalt paving layer is thereby enhanced.