Rachel Weisz announced that she will not be reprising her role of Evelyn due to different interests with the screenplay. Later on, Maria Bello was announced to replace her.
The tomb of the Dragon Emperor with its Terracotta warriors is inspired by the real-life tomb of the first emperor of the Qin Dynasty. The mausoleum is located in Xi'an, China.
Brendan Fraser, who plays Rick, was born in 1968, and Maria Bello who plays Evelyn, was born in 1967, while Luke Ford, who plays their son Alex, was born in 1981 and is only 13 years younger than Fraser and 14 years younger than Bello.
In the tomb scene, the small device that triggers one of the traps by dropping a bronze marble from the mouth of a dragon to the one of a frog is inspired on a real machine, an ancient construction consider to be the first seismograph that could predict the direction of a coming earthquake.
The crossbow traps in the tomb scene are also based in reality. Actually, one of the reasons why the terracotta army diggings are going so slowly is that, according to Chinese archaeologists, the site is filled with traps similar to the ones depicted in the movie.
The bar where the O'Connells and Lin go back to after the battle with the emperor is named "Imhotep". It is also the name of the High Priest in _The Mummy (1999)_ and _The Mummy Returns (2001)_.