The film is based on an ancient Chinese poem called The Ballad of Mulan, in which Hua Mulan - the daughter of a famous warrior - disguises herself as a man to fight in her father's place in China's imperial army.
When the original animation was released, it won fans all over the world for its modern animation style, loveable characters and catchy songs.
The trailer suggests that the new film will be slightly different to the original animation.
Find out more below.
In the new film, there is a greater focus on reality, rather than the fantastical nature of the animated film.
Rumours have been flying around that songs will not feature in the remake in the same way that they did in the animated original, which some fans are not happy about at all.
A report from US magazine DisInsider suggests that the songs will be purely instrumental.
Those who are more supportive of the decision say that the live-action film will be more faithful to the original story of Mulan.
They are looking forward seeing Mulan represented as a true warrior in imperial China, complete with martial arts and epic battles.
Another difference spotted by fans in the trailer was that the wise-cracking dragon Mushu, who helps Mulan on her journey to become one of China's greatest warriors, does not appear in the trailer.
The mischievous cricket doesn't feature either.
It is widely believed that the comedy duo won't be appearing at all in the film. There was a rumour of a phoenix playing a similar role in the live-action remake instead, according to DisInsider, but this has not been confirmed.
That's not the only sidekick news though - we know that Xana Tang will play Mulan's sister.
She was not a character in the animated movie, but this casting brings the remake more in line with the original ballad, in which Mulan had a brother.
Another difference that has got Mulan fans talking is the decision to get rid of Mulan's original love interest - Captain Li Shang.
Instead, he will be replaced by a rival to Mulan - Chen Honghui - played by Yoson An, who takes a romantic interest in Mulan as her true identity is revealed.