The intercalation of FeCl₃ into graphite with molten salt method has been synthesized. Its structural stability and thermal stability both in air and some liquid media for some time were investigated by using the XRD as well as TG-DTG techniques. The obtained results show that FeCl₃-GICs are quite stable in air,higher stable in water and acid liquid media,but less stable in alkalic liquid media and some organic solvents. The degradation temperature of FeCl₃-GICs is about 330 ℃.