Abstract: Objective To explore the relationship of changes of amide A in rabbit heart and the postmortem interval（PMI） by FTIR spectroscopy technique. Methods Thirty-two rabbits were sacrificed and the hearts were sampled at 20 ℃ within 48 h postmortem points. All samples were sliced and tested by FTIR spectroscopy technique. The images of amide A were created by FTIR spectroscopic imaging. The positive and negative area ratios of amide A were analyzed using imaging analysis system. Results The positive and negative area ratios declined regularly with the prolongation of death time in 48 h. There was a significant quadric relationship between the area ratios（y） of amide A（positive and negative area） and PMI（x）. The regression equation was y=0.001 x²-0.038 x+0.747（R²=0.940）. Conclusion The ratios of positive and negative area of amide A showed a strong correlation with PMI and could be used to estimate PMI.

Key words: forensic pathology, spectroscopy, Fourier transform infrared, myocardium, amide A, postmortem interval, rabbits