Amorphous carbon films with a smooth surface and a good adhesion to silicon and steel substrates were prepared by ion beam assisted deposition (IBAD) using a single ion source. The energy of Ar ion ranged from 400 to 1500 eV. The structure and composition of the films were characterized using Raman spectroscopy, FTIR, HRTEM, TED, SEM, ERD and RBS. Electrical resistivity, microhardness and friction coefficient were tested to evaluate the films. The films was proved to be diamond like carbon (DLC). The hydrogen content measured by ERD is about 2. 05 at. -%. The carbon hydrogen bond (C-H) seemes unformed. As ion energy and beam current increased, microhardness and friction coefficient increased, but electrical resistivity decreased. The increased microhardness is due to the increased film density and the decreased electrical resistivity is due to the decreased concentration of sp 3 bonds in the film.