The move has prompted National Union of Journalists members at the FT to threaten to take industrial action.
According to the NUJ, the FT journalists have been told they face possible redundancy if they decline to move to China.
At a union meeting held at the paper last week, FT journalists unanimously backed a motion which said: "We condemn the outrageous treatment of journalists on FT Chinese.
"We demand no redundancies on FT Chinese and that the journalists be placed on the same terms and conditions as the rest of FT editorial.
"It is unconscionable that the FT is sending FT Chinese journalists into harm's way. We will ballot for industrial action if these demands are not met."
According to the NUJ, two of the four journalists affected are British citizens.
One of the four journalists working on FT Chinese said in a letter to NUJ colleagues: "Last year we finally broke even, which is absolutely an achievement worth celebration.
"However, just as we were contemplating what to do to further enhance our position, there came this horrible and stunning decision of redundancy from the management.
"Needless to say, it was a tremendous shock to the entire team. This reminded us of a very old Chinese saying: 'kill the donkey after it has done its job at the mill'."
The journalist who wrote the letter said that Chinese law forbids Chinese nationals from working for foreign media inside the country.
They added that journalists working on FT Chinese already have lesser pay and conditions than journalists working elsewhere on the FT.
A spokesman for the FT: "We are surprised by the NUJ statement. Our position has always been that this is a proposal and that we wouldn't move forward until the individuals concerned were comfortable with that proposal."
Dominic Ponsford is the editor of Press Gazette