Aluminum Titanate ($Al_2TiO_5$) is a ceramic material with coefficient of low thermal conductivity and high thermal shock resistance. The micro cracks formed during the sintering of $Al_2TiO_5$ lead to low mechanical strength. Various oxide additives are used to improve mechanical properties. In this study, $SiO_2$ was used as additive and its effects on porosity, phase composition, bending strength and microstructure were investigated. The compositions were prepared by adding up to 10% (by wt.) quartz ($SiO_2$) to the equimolar mixture of $alpha-Al_2O_3$ and rutile ($TiO_2$). The powder mixture was shaped by an uniaxial press and sintered at 1450 °C for 3 hours. Experimental results show that porosity decreases and mechanical strength increases with the addition of $SiO_2$. It was determined that mullite formation occurred and the number of cracks decreased with the addition of $SiO_2$. The bending strength of the pure $Al_2TiO_5$ was 6.80 MPa, while the bending strength of 38.43 MPa was obtained by addition of 10% $SiO_2$. As a result, the addition of $SiO_2$ has played an active role in improving the physical and microstructural properties of $Al_2TiO_5$ ceramics.