Films opposing Japanese aggression and imperialism prevailed from the early 1930s, when the Japanese imperialists invaded northeast China after plotting the September 18th Incident of 1931 till the end of the 1940s. Twenty-one works created in this period mainly depict the Chinese people rising in resistance against Japanese aggression.

As the national anthem says, "The people of China are in a most critical time. Everyone must roar his defiance." Movies with a spirit of fighting against imperialism and Japanese aggression became the sound of a bugle, loud and encouraging.

Judging from their content and ideological features, fine movies of the fight against imperialism and Japanese aggression can be divided into three stages. The first stage mainly reflects the disasters brought about by the invasion of China by the Japanese imperialists and the awakening of the Chinese people. The screenwriters and directors concentrated their efforts on encouraging and arousing the enthusiasm of the people in the struggle against Japanese aggression.

The period from July 1937 to August 1945 constituted the second stage, a period of fighting in an all-round way against the Japanese aggression. Films produced during this stage depict directly the heroic spirit and actions of the Chinese people in the Anti-Japanese War.

The period from August 1945 to 1949 was the third stage. Films put out in these years have a profound connotation. They are a post-victory review and pondering by Chinese cinema artists of the great war waged by the Chinese people against Japanese aggression and they analyze the source of power and the reason for final victory.

Defend Our Land produced and directed by Shi Dongshan was the first film to directly show the Anti-Japanese Aggression. It tells the story of a farmer named Liu Shan. After the September 18th Incident of 1931, Liu leaves his native place in the northeast and takes his wife and younger brother to find shelter in a small town in the south. Soon afterwards, war breaks out again. Liu Shan and his wife mobilize the townsmen to fight against the enemy alongside the defending troops. But his younger brother, an idler, is bought over by a traitor. The brother turns a deaf ear to Liu Shan the whereabouts of the traitor. In the end, the soldiers and the townsmen unite, kill the traitor and charge into the enemy ranks. The movie contrasts the awakened Liu couple against their younger brother to lay bare the crimes of the Japanese aggressors, lash out at the cowards in the Chinese nation, and sing the praises of the heroic people.