Magnesia ceramic with excellent sintering properties and thermal shock resistance was prepared by using coprecipitation method, and the nanometer magnesia, titanium(IV) sulfate and ammonia as raw materials. The samples sintered at 1450℃ and 1550℃. The mechanical properties at room temperature, thermal shock resistance, analysis and characterization were characterized by the XRD and SEM methods. The effect of the TiO₂ on sintering property and thermal shock property of magnesium oxide ceramics were studied. The result shows that Mg₂TiO₄ and MgTiO₃ were generated by TiO₂ and MgO which in the grain boundaries to hinder the growth of the grain. The linear change rate and relative density of the sintering samples increased first and then decreased. When the content of TiO₂ is 4% and the sintering temperature is 1550℃, the relative density of the sample is maximum, 98.64%. It illustrated that the sintering process of MgO ceramic was promoted by TiO₂. The Mg₂TiO₄ and MgTiO₃ in the grain boundaries slowed the tip stress of the cracks and hindered the cracks extend. It make the thermal shock behavior of MgO ceramic improved effectively.