To obtain an asphalt composition that has an excellent adhesivity in a temperature range of 5-50C and is usable throughout a year even outdoors.

The asphalt composition comprises 8-14 mass% of a thermoplastic elastomer, 1-5 mass% of a resin acid and 20-60 mass% of a petroleum-based solvent extracted oil and the rest of asphalt and has the total acid value of 1.5 mgKOH/g. The adhesive sheet is obtained by forming an adhesive layer composed of the asphalt composition on one side of a substrate such as a nonwoven fabric, etc.