Al2TiO5/Al2O3 composites with various Al2O3 contents were prepared. The phase compositions and microstructure evolution of the samples were observed via XRD and SEM, respectively. The thermal properties, including thermal expansion ratios and the erosion resistance of the Al2TiO5/Al2O3 composites to molten Al, were investigated. The experimental results show that the relative densities of the prepared Al2TiO5/Al2O3 composites are proportional to the Al2O3 content, and that the composite samples with high Al2TiO5 contents have good erosion resistance to molten Al.