Abstr act The effect of the addition of Nepheline syenite on the sinter ing, and pr oper ties of a sanitar ywar e por celain body was studied. Two cer amic bodies wer e compar ed: a commer cial sanitar ywar e body and one, wher e 40% of the mass of Na feldspar was substituted nepheline syenite. The sinter ing was evaluated by the linear shr inkage, the water absor ption. Samples, the bending str ength. The addition of Nepheline syenite had a positive effect on the for mation of the liquid phase dur ing the sinter ing. The sinter ing and the mechanical pr oper ties wer e I ndex Terms Nepheline cyanide, sinter ing, sanitar ywar e, cer amic