The role of the Little (Young) Soldier was originally written for Jackie Chan, who came up with the idea of the story Little Big Soldier 20 years ago. However, it took 20 years to wrap up the script, and now Jackie Chan is cast as the Big (elder) Soldier instead. Leehom Wang takes the role of Little (young) Soldier.
When he could not take the role of the young general, Jackie Chan originally considered Daniel Wu to play the part of the young general, but Chan disregarded the thought after realizing that he had already filmed two movies earlier with Wu. Chan's wife, Joan Lin, suggested their son Jaycee Chan, but Chan objected to it. Lin later suggested Leehom Wang, whom Chan agreed to immediately.
At a conference in Beijing on 20 November 2009, Jackie Chan announced, along with Universal Culture Limited and EURO WEBSOFT, that an MMO is being released to promote the film. Chan and Wang's characters in the game were also shown at the conference. On 26 January 2010, the MMO went online under the name FLASH Little Big Soldier. It is free to play under an account subscription. However, the game is available only in Chinese.