Abstract: Aquathermolysis reaction of heavy oil in the presence of metallic salt and formation mineral was studied.A five-lumped kinetics model,comprising of gas, saturate, aromatic, resin and asphaltene, was established on the basis of experimental results.The reaction rate constant and the activation energy were calculated by using the Runge-Kutta integral and complex method. The results indicated that resin was the center of reactions and main source of light component increase such as gas, aromatic and saturate.Asphaltene changed into resin mainly.The model prediction was consistent with the experimental data,which suggested that the five-lumped kinetics model is reasonable.