Abstract: SEM and EDS characterization have provided insight into the chemical composition and microstructure of a particular kind of HPHT synthesized diamond abrasive.Fine dispersion of micron titanium compound particles was observed both on surface and inside the diamond grains.The particles were found to be removed from the grain surface by oxidation and subsequent acid corrosion.After such treatment, porous structures were formed on the diamond grain surface.The possible beneficial effect of the porous structure, such as self-sharpening performance and high grinding efficiency of diamond wheel is suggested.