Abstract: Micro millgrinding is a novel machining technology with characters of micro milling and micro grinding. To provide theoretical support and data reference for parameters optimization of the micro millgrinding tools， different materials were machined with the cubic boron nitride micro millgrinding tools. The influence of the tool diameter and abrasive particle size on workpiece surface quality were analyzed and compared with those of micro milling. The results show that if appropriate tool parameters are used in micro millgrinding，submicron surface roughness will be obtained and it is better than that machined by micro milling. Smaller particle size or larger tool diameter will make surface quality better to some extend in micro millgrinding，and the influence of particle size on surface roughness is more significant.

Key words: micro millgrinding, abrasive particle size, tool diameter, surface roughness, surface topography