Diamond coating had been applied as a new candidate material for MEMS and NEMS besides the protective coating of tools and dies. Micro-texturing became a key technology to build up the micro- and nano-structures into diamond films for application to sensors and devices. High density oxygen plasma etching method was developed as a tool to construct any tailored micro-textures into the CVD diamond coating. First, the quantitative plasma diagnosis was utilized to describe the plasma state suitable for this micro-texturing via the etching process. In second, the CVD-diamond coated WC (Co) substrates were prepared to imprint the initial two dimensional micro-dot patterns by the ink-jet printer. The diameter of micro-dots as well as their spatial alignment in printing was varied to investigate the geometric resolution of oxygen plasma etching. Optical microscope, SEM and Raman spectroscopy were utilized to make quantitative characterization on the etched micro-textures into the diamond films. Laser-microscope as well as surface profilometer was also used to describe the geometry and dimension of micro-groove and micro-disc patterns on the diamond-coated WC (Co) substrates.