Disclosed herein are slurry compositions for use in CMP(chemical mechanical polishing) process of metal wiring in manufacturing semiconductor devices, comprising a peroxide, an inorganic acid, a propylenediaminetetraacetate(PDTA)-metal complex, a carboxylic acid, a metal oxide powder, and de-ionized water, wherein the PDTA-metal complex plays a major role in improving overall polishing performance and reproducibility thereof by preventing abraded tungsten oxide from readhesion onto the polished surface, as well as in improving the dispersion stability of the slurry composition.