Two-dimensional (2D) correlation FTIR spectroscopy was used to investigate the dynamic mechanism of poly(aspartic acid) during the heating process. According to the 2D asynchronous correlation spectra, the C=O vibration band of Amide I was separated into three peaks at 1637, 1645 and 1677 cm−1, assigned to α helical, random coil and β antiparallel conformation, respectively. And α helical structure would transform into the more ordered and stable conformation of β antiparallel in heating. In the region of 3700–2700 cm−1, the H-contained groups were analyzed; the loosening of hydroxyl is found to change prior to the NH-related hydrogen bonds and the conformational reorganization of hydrocarbon chains.