从“九·一八事变”到“八·一三事变”，是国内革命战争向民族革命战争转变的时期。这一时期，根据国际形势的发展、国际关系的变化、国内政治斗争的状况以及社会主要矛盾的演变，国共两党在对日政策问题上均提出了自己相应的主张。本文根据有关史料对国共两党此间对日政策的演变及其成因作了探讨。 From the “September 18 Incident” to the “August 13 Incident” was a period of transition from the revolutionary revolution in China to the revolution in the ethnic revolution. During this period, according to the development of the international situation, changes in international relations, the status of domestic political struggles and the evolution of major social conflicts, the KMT and CPC both raised their own views on the issue of Japan’s policy. Based on the relevant historical data, this article explores the evolution of the policy of the Kuomintang and the Communist Party during the Japanese occupation of Japan and its causes.