Abstract: In order to directly investigate the change of chemical bond between tanning agents and collagen molecule, hide powder tanned by aluminum, silicon and phosphorus tanning agents were prepared. The chemical shifts of Al, Si and P in hide powder tanned with Al, Si and P tanning agents were analyzed by solid-state ²⁷Al NMR, ²⁹Si NMR and ³¹P NMR, respectively. The results showed that the chemical shift of Al in the aluminum tanned hide powder, in which collagen molecules were crosslinked through coordination bond, could be regarded as unchanged after hydrothermal denaturation (only slightly shift to high field area). The chemical shift of Si in the silicon tanned hide powder, in which collagen molecules were crosslinked through hydrogen bond, did not change after hydrothermal denaturation. The chemical shift of P in the phosphorus tanned hide powder, in which collagen molecules were crosslinked through covalent bond, changed a lot after hydrothermal denaturation, and its chemical shift was obviously shifted to the high field area.