Using a molten metal bath as heat source of reaction, the coking kinetics of Gudao vacuum residue in temperature ranges of 400-440 degrees C and 460-500 degrees C were studied and kinetic models were developed. The order of reaction, pre-frequency factor and apparent activation energy of thermal-cracking were determined as 1.0, 7.853 X 10(10) min(-1) and 175. 3KJ/mol respectively. The results laid a solid foundation for technological computation, reconstruction and design of the tubular furnace using the residuum as its feedstock.