A total current spectroscopy measurement has been performed on Si(lll)7×7 surface. Four peaks at 2.6, 5.2, 8.6, and 12.9 eV above vacuum level have been observed on clean surface, assigned as A, B, C, D respectively. Among them, the peak A contributed by the surface state is identified by hydrogen adsorption experiment. A preliminary explanation of the experimental result has been made.