Two-dimensional Ti3C2 nanosheets were obtained by exfoliation of synthesized Ti3AlC2 powders in 40% HF solution at room temperature. The influence of etching time on the synthesis, structural evolution during heating, and thermal stability of as-prepared Ti3C2 nanosheets were studied. The graphene-like structure of as-prepared Ti3C2 nanosheets was confirmed by XRD and SEM. TG–DTA and elemental analysis suggested that the OH and F groups attached on the surface of Ti3C2 nanosheets could be eliminated by heat treatment. It is noteworthy that Ti3C2 nanosheets are thermal stable up to 1200°C in Ar atmosphere. In the heating process, a small quantity of TiO2 anatase emerges at 500°C and then reacts with Ti3C2 to form a solid solution of TiCxO1−x (0<x<1) with the increase of temperature.