The Spring River Flow East, co-directed by Cai Chusheng and Zheng Junli, brought to the screen in a broad scope, with its description of a family's joys and sorrows, the struggle and miseries of the Chinese people during the war and the bullying and humiliations they continued to suffer after the war. It helped the people clearly realize what was all about.

There are three threads linking the plot of the film. The first is the bitter life led by Sufen, her mother-in-law, and her child, which is an authentic record of the poverty and sufferings of the people in the enemy-occupied and Kuomintang-ruled areas. It plays a strong role of accusation. The second thread is the change of Zhang Zhongliang, the male leader, from a patriotic young man who opposes Japanese aggression to a man who worms his way into the corrupt upper-class society. With this thread at the center, the film portrays a batch of politicos and bureaucratic traders, fully exposing the crimes and the luxurious and debauched life of the Kuomintang bureaucratic ruling clique, who ignore the national crises and the life or death of the people and amass ill-gotten gains when the nation is in a crisis. The third thread shows that Zhang Zhongming, the younger brother of Zhang Zhongliang, joins the guerrilla forces active in a mountain area and continues to work there after China is liberated.

The interwoven development and the comparison of the three plot threads present a true picture of the reality in China before and after the Anti-Japanese War. In her last word to her son before committing suicide at the end of the film, Sufen writes, "Don't learn from your father but from your uncle." These words greatly deepen the theme and are a conclusion of the screenwriter's thoughts about reality. The film was regarded as the first epic in the history of Chinese cinema and received an unprecedented warm welcome. It was shown continuously for three months in Shanghai and the audience reached 700,000 person-times, setting a new record.