Seismic exploration using artificial sources was conducted at Usu volcano, Japan in November,2001 by 58 participants from nine national universities, Japan Meteorological Agency, Japan Nuclear Cycle Development, and Institute of Physical and Chemical Research to investigate subsurface seismic structures. The exploration was the eighth joint experiment under the National Project for Prediction of Volcanic Eruptions. A total of 288 temporal stations equipped with a 2Hz vertical component seismometer and a portable data logger were deployed in and around Usu volcano and Toya caldera. Dynamite shots with charges of 200-250kg were detonated at seven locations andseismic signals were successfully recorded. To reveal the P-wave velocity structure, first arrivaltimes were picked from the seismograms and 1877 useful arrival times are listed in this paper. From the record sections and the arrival time data, characteristics reflecting the geological structure of the experimental area were identified.