The theory of dissipative structure is applied to the study of atherosclerosis. An autocatalytic theoretical model is suggested. The behaviors of the model are in agreement with the facts of experimental atherosclerosis. We predict the high effectiveness of combinative therapy for atherosclerosis with drugs affecting protein metabolism and lipid metabolism. It was verified by animal experimentation. Further possible developments are briefly discussed. This work is the theoretical foundation of the Multi-Risk Factor Intervention trial (MRFIT) which is popularized clinically in its beginning all over the world.