Abstract: The author thinks that Mao Zedong took the whole situation of Chinese anti-Japanese war into a systematic consideration and had the following viewpoints: 1. Viewing the anti-Japanese war, his objective of study, as a system; 2.As viewed from the totality of the system and its organic connection, analyzing the basic peculiarities of both sides of ourselves and the enemy in anti-Japamese war; 3. Holding the origin and evolution of the war in historical dynamic system; 4. Stressing the relations between the structure and function of war factors; 5. Illustrating the relations between playing the subjective activity in the war and the preferred orientation and optimization method of war system. These systematic viewpoints of war are the important methodology to realize scientific prediction in the anti-Japanese war.