The Schottky barrier width (W-dep) formed at MoO3-doped p-type C-60/Ag interface was evaluated by low-frequency capacitance measurements. At relatively low-doped concentration of 3000ppm, W-dep was determined to 57nm and the clear rectification behavior was observed. On the other hand, at heavily-doped concentration of 10000ppm, W-dep shrunk to 23nm and the quasi-ohmic behavior due to the tunneling current was observed. Heavy doping technique can be applied to the fabrication of ohmic C-60/metal contact.