The present invention discloses a polishing slurry, wherein, the said polishing slurry contains polishing abrasive grains and a carrier, it further contains a reagent which has two functional groups. The polishing slurry of the present invention can reduce the concentration of the abrasive grains in the polishing slurry and lessen the downwards polishing pressure required in a CMP process, thereby it can improve the quality of the substrate and minimize the rate of defect, at the same time it can keep the desired polishing rate.