Evidence items have been collected and kept in the Memorial Hall as proof of the Japanese invaders' atrocities during World War II.
The latest pieces include a supplement to Japanese newspaper Asahi Shimbun dated Dec. 17, 1939, and carrying two photos of Japanese troops holding an "entry ceremony" after occupying Nanjing.
They were donated by a Japanese man surnamed Ohigashi ahead of the 74th anniversary, said Zhu Chengshan, curator of the Memorial Hall, adding the same man had earlier donated more than 1,000 items.
"Every year, more than 5 million people pay visits to the Memorial Hall to deepen their understanding about the history of massacre," he said.
Chen added more than 10 Chinese and foreign experts have been invited to compile a dictionary of the history of the Nanjing Massacre.
"The Flowers of War", a film depicting the Nanjing Massacre and directed by China's famous director Zhang Yimou, will hit the screen on Friday. It tells the story of 13 sex workers in Nanjing who volunteer to replace university students as escorts for invading Japanese soldiers.
During Tuesday's rally, a Nanjing Peace Declaration was issued and read out on behalf of local residents by citizen Zhou Xue. "We Nanjing people pledge to take history as a lesson, cherish peace and create the future," it said.
"We will help humankind eliminate prejudices through communications, enhance cooperation through development, and build a harmonious world together."