The structure and dynamic properties of aqueous mixtures of 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) have been investigated over the whole range of HFIP mole fraction (x(HFIP)) by large-angle x-ray scattering (LAXS), small-angle reutron scattering (SANS), F-19-, C-13-, and O-17-NMR chemical shifts, O-17-NMR relaxation, and mass spectrometry. The LAXS data have shown that structural transition of solvent clusters takes place at x(HFIP)similar to0.1 from the tetrahedral-like hydrogen bonded network of water at x(HFIP)less than or equal tosimilar to0.1 to the structure of neat HFIP gradually formed with increasing HFIP concentration in the range of x(HFIP)greater than or equal to0.15. The Ornstein-Zernike plots of the SANS data have revealed a mesoscopic structural feature that the concentration fluctuations become largest at x(HFIP)similar to0.06 with a correlation length of similar to9 Angstrom, i.e., maximum in clustering and microhetrogeneities. The F-19 and C-13 chemical shifts of both CF3 and CH groups of HFIP against x(HFIP) have shown an inflection point at x(HFIP)similar to0.08, implying that the environment of HFIP molecules changes due to the structural transition of HFIP clusters. The O-17 relaxation data of water have shown that the rotational motion of water molecules is retarded rapidly upon addition of HFIP into water up to x(HFIP)similar to0.1, moderately in the range of similar to0.1