Ash of Antarctic krill integument (AAKI) was prepared by sintering the integument at 550°C under air atmosphere for 4 hours, and its composition was analyzed by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and electron dispersive spectroscopy (EDS). XRD results showed that the major phase in AAKI was ascribed to apatite. Besides, it was noticed that the (300) peak of AAKI shifted to 33.07°, which was coincident with that of fluorapatite (FA). The FTIR results confirmed the presence of phosphate ions, and the absence of -OH. The EDS results confirmed the presence of Ca, P, O and F elements in the ash sample. The content of FA in the ash was determined to be 50.4%, and the proportion of fluorine in the form of FA to the total fluorine in the integument was 40.5%. Based on the XRD, FTIR and EDS results, it can be concluded that FA was the main form of fluoride in the integument of Antarctic krill.