A combined method of electrical resistivity tomography and dye tracer test was tested for monitoring of water infiltration in an undisturbed forest soil developed from granite. A 1 m * 1 m acryl frame was installed on the leveled surface and 3 lines of electrodes were installed in the framed area. The framed area was flooded with 300 L of Brilliant Blue FCF solution at 5 g L^-1 and the electrical resistivity was measured before and after the flooding. After 3 days of the flooding, the framed profile was vertically excavated at 10 cm interval and the vertical stain image was also recorded using a digital camera. The dye stain images revealed 4 types of infiltration patterns in the profile: matrix flow in A horizon, lateral flow at the interface of A and C horizons, fingering in the upper part of C horizon and macropore flow in C horizon. The stain images and the electrical resistivity images were matched very well. The result of this study indicates that the electrical resistivity tomography can be utilized for the monitoring of water infiltration in a soil profile.