Deposition of diamond on silicon substrates has been performed by RF HPCVD (Helicon Plasma Chemical Vapor Deposition) from methane-hydrogen gas mixture. Growth properties and deposition condition conditions have been studies as functions of substrate temperature ($750^{circ}C$~$850^{circ}C$). Si p-type (100) wafers were used as a substrate. The chharecterizations of the gaind thin films by SEM, AFM and Raman seattring are diamond crystallites which include disordered graphit.