To investigate the influence of ferroelectric phase LiNbO3 on mechanical properties and structure ofAl2 O3 ceramic material，in this paper，LiNbO3 /Al2 O3 composite materials were prepared using Al2 O3，Nb2 O5 andLiCO3 as the starting materials through high temperature solid state method and hot pressed sintering method． Thephases，mechanical properties and the microstructure of the composites were studied． The results showed that theaddition of LiNbO3 was helpful to the sintering of Al2 O3 and the sintering temperature of Al2 O3 ceramic material wasalso decreased． When the sintering temperature over 1 200 ℃，the main phases of the composite materials still wereLiNbO3 and Al2 O3，but a small amount phase of LiNb3 O8 existed because some Li elements were volatilized． Thebending strength of the 5vol%LiNbO3 /95vol%Al2 O3 composite materials was the highest ( 162. 34MPa) after sinte-ring at 1 200℃ for 3 hours in air． The relative density of 15vol%LiNbO3 /85vol%Al2 O3 composite hot- pressed at 1300℃ under a pressure of 150 MPa for 1h was 90. 82% and the bending strength and fracture toughness were393. 94MPa and 2. 38MPam1 /2，respevtively． Non- 180° domains formed in LiNbO3 grains in the composite，whichcontributed to the improving of the mechanical properties of the composite．