Abstract: Through radical copolymerization , modified waterborne poly methacrylic acid (MPMA) with hydrophilicand hydrophobic group s was prepared by reacting ally poly (ehtenoxy ether) , methacrylic acid and methyl methacrylate. Using MPMA as ceramic dispersant , the effect s of MPMA concent ration on the rheological behavior of Diamond/ Feldspar/ Clay compound slurry and ceramic breaking st rength were studied , and simultaneously the reasonsand dispersive mechanism were analyzed. The result s show that MPMA can improve the slurryps rheological properties and the ceramic st rength. The optimum MPMA concent ration is 0. 57 wt % (based on the absolute dry slurry)with p H ranging from 9 to 10. When adding 0. 57 wt % MPMA , the slurryps negative Zeta potential increases from²8. 5 mV to 65. 5 mV , and it s zero shear viscosity decreases from 690. 9 mPa·s to 81. 6 mPa·s. At the same time , it sthixot ropy area reaches the minimum , and the slurry exhibit s Newton flow behavior. Compared with ceramic withinorganic dispersant addition , the ceramic with MPMA addition owns higher breaking st rength , which is increasedfrom 160 MPa to 268 MPa.