狄仁杰
For the lead role as Di Renjie, Tsui originally had Tony Leung Ka-fai, along with Tony Leung Chiu-wai, and Jet Li in mind. Li mentioned while promoting Tsui's other film, "Flying Swords of Dragon Gate", that he had a chance to read the script though he wasn't able to be part of the project due to some unknown reason. Tsui commented on choosing an actor to play Di Renjie: "Who said that Di Renjie must be plump and old? He could also be very handsome. Wits and looks can balance one another." On 5 January 2009, "The Hollywood Reporter" announced that Andy Lau would star in the lead role. On 29 April 2009, it was announced that Carina Lau, Li Bingbing, Deng Chao and Tony Leung Ka-fai would appear in supporting roles.