A mineral having the chemical formula of BaCe(CO3)2F newly found in China is called Hwanghoite and may be named from the structural point of view as barium-synchysite.It is shown by X-ray examination that the crystal structure of this mineral has the pseudo rhombohedral unit cell with α=5.1?, c=19.6? and space group C34- R3. The unit cell contains three molecules of BaCe(CO3)2F. The positions of the heavy-atoms are located by the symmetry of the space group and verified by the single crystal X-ray diffraction intensities, while that of the light-atoms are deduced from geometrical and chemical considerations on the basis of the heavy-atom positions.The reliability of the pseudo structure so obtained is discussed and the important aspects of the structure are compared with similar known minerals.