Abstract: Objective To observe the chemical groups changing in rat kidney with regard to fatal hyperthermia by Fourier transform infrared microspectroscopy （FTIR-MSP） and to provide a new method to diagnose fatal hyperthermia. Methods Rats were sacrificed by hyperthermia, brainstem injury, massive hemorrhage and asphyxiation and divided into groups. The renal samples were dissected immediately after death. The data of infrared spectroscopy in glomerulus were measured by FTIR-MSP. Results The absorbances of 3 290, 3 070, 2 850, 1 540 and 1 396 cm-1 significantly increased （P<0.05）, and the ratios of A1 650/A3 290 and A1 650/A1 540 significantly decreased （P<0.05） in group of hyperthermia. Conclusion FTIR-MSP can analyze the changes of chemical groups of kidney as an auxiliary diagnosis for discriminating hyperthermia with other causes of death.

Key words: forensic pathology, spectroscopy, Fourier transform infrared, cause of death, hyperthermia, kidney, rats