It was inspired by Iris Chang's book The Rape of Nanking (1997), which discussed the persecution and murder of the Chinese by the Imperial Japanese Army in the then-capital of Nanjing at the outset of the Second Sino-Japanese War (1937–45).

Contemporary actors play the roles of the Western missionaries, professors, and businessmen who formed the Nanking Safety Zone to protect the city's civilians from Japanese forces.

In order to protect Chinese civilians, a small group of European and American expatriates, Western missionaries, professors, and businessmen banded together to save 250,000, risking their own lives.

"[2] Nanking has received numerous positive reviews, including one from Reuters that says that the "beautifully crafted film...honors the highest calling of documentary filmmaking."

[4] Japanese right-wing nationalist[5] filmmaker Satoru Mizushima called the film a "setup by China to control intelligence," and plans to release his own documentary, The Truth about Nanjing, in which the massacre is portrayed as merely political propaganda.