Abstract: The cryolite-type fluorides Na₃FeF₆ was successfully synthesized under mild hydrothermal condition.The structures of the compound was determined by means of powder X-ray diffraction analysis.Na₃FeF₆ has a monoclinic structure with lattice parameter a = 5.513,b= 5.728,c = 7.964.The compound was further characterized by scanning electron microscopy,thermogravimetric,differential thermal analysis.The variable temperature magnetic susceptibility of the compound was characterized and the result showed that the magnetic ordering was related to the crystallographic features and isolated magnetic unit with the temperature decreasing.