Recently, tomographic analysis has been applied to the seismic refraction survey for tunnel geological investigations. In tomograpic analysis, it is important to use appropriate initial velocities. Therefore, 5 methods to set initial velocities were examined by using geological observation records at the tunnel face. The results showed that slight difference in a coincidence with geological observation records was recognized among tomographic solutions leaded by the 5 setting methods. However, the tomographic solutions by initial velocities setting method from 2 simple travel time analyses showed well coincidences with the geological observation records. In this paper, we report the problems and setting methods of the initial velocities in tomographic analysis.