We develop a novel and simple method to prepare rutile TiO2 nanosheets with {010} exposed facets by vacuum heat treating Ti3Si0.9Al0.1C2. Exposed facet area of the nanosheets can be more than 20μm2. Formation of the nanosheets is a diffusion control process. In the initial stage, most of the nanosheets are parallel to the {0001} planes of Ti3Si0.9Al0.1C2 because of the rapidly outward diffusion of Ti atoms along these planes. However, the diffusion of Ti atoms in the TiO2, Al2O3 and SiO2 mixture layer domains the growth of nanosheets gradually with the increase of the thickness of the oxide scale.