Abstract: Conventional microhardness test were employed to characterize the mechanical properties of magnetron sputtered diamond-like carbon thin films of thickness of 0.09-0.56 mirons. It was found that microhardness of magnetron sputtered DLC varies with sputtering parameters in a systematic way and it can be related to the diamond-like properties and the component of SP² and SP³ structures of the DLC. Analysis from DLC of 0.3073μm which were simu-taneously sputtered onto stainless steel and single crystal silicon substrate at 200W showed that the true hardness of the DLC was ranging between HV 6000-6600, which is close to the hardness of natural diamond. Pronounced indentation size effect (ISE) was observed, and the ISE index of 1.9 for the DLC was obluined.