In order to investigate the structure and morphology of diamond-like carbon (DLC) film coated on a polymer alloy prepared by a particular four-steps method in the plasma-based ion implantation and deposition (PBIID) process, studies were made on the structure and properties of the DLC film with special reference to its surface morphology by scanning (SEM) and transmission (TEM) electron microscopies. It is revealed from TEM microscopy that the amorphous structure of the DLC film consists of a silicon-implanted layer on the polymer substrate, a hard acetylene-implanted layer and a flexible acetylene/toluene-deposited layer. Some properties of the DLC film can be accounted for by the morphology examined in this study.KEY WORDS diamond-like carbon / DLC / coating / plasma / implantation / polymer alloy / TEM / XPS 1