Both Gong Li and Maggie Cheung were originally considered playing the queen's role. When Ziyi Zhang took over the part, the script was rewritten to make the character younger.
Actress Shao Xiaoshan said she substituted for Ziyi Zhang in some bathing and sex scenes. However, she is not listed in the credits. "If they don't add my name to the cast list, audiences will think that all the nude scenes were done by Zhang herself, which will be totally cheating me. I gave my body to the audience. I don't care whether my name is on the credits but I just want to tell the public that I did the nude scenes," Shao said on her blog.
At Cannes film festival, Zhang Ziyi told the media that she did not appear nude in the movie, indirectly confirming that she had a stand-in for the nude scenes.
At 180 meters long and 60 meters wide, the set for the Emperor's Palace is the largest set ever built in China.
The film never shows who stabs Empress Wan. One interpretation is she was killed by the spirit of her late husband. Asian film critic Bey Logan offered a theory that she was actually slain by her handmaiden, Ling. Logan points out the numerous shots focusing on Ling (a seemingly unimportant character who never speaks) as evidence she was to be revealed as the assassin.
Gong Li was originally supposed to play Zhang Ziyi's part. Due to scheduling conflicts, the role was passed onto Ziyi Zhang and she gladly accepted because she thought the character was so interesting.