Raman spectra were collected for tetrahydrofuran (TI-IF) hydrate, a structure II clathrate hydrate (CH) that was prepared from THF and a dilute solution of D2O in H2O (5% D2O) in a 17:1 ratio. The vibrational modes observed include (1) the uncoupled O-D vibrational modes of HDO in H2O between 10 and 170 K and (2) the THF ring breathing mode (predominantly C-C-C-C stretches) between 10 and 170 K. The low-frequency host lattice modes and the THF C-H stretching modes at 10 K are also presented. The spectral line attributed to the C-C-C-C vibrational mode of the enclathrated THF molecules broadened, and a pronounced shoulder developed on the low-frequency side as the temperature decreased. This anomalous behavior is attributed to the inhibition of rapid reorientational motion of the enclathrated THF molecules at T < 100 K. Analysis of the uncoupled O-D vibrations indicates that the frequency increases land thus the hydrogen bond strength decreases) with increasing temperature. The vibrational frequency of the uncoupled O-D oscillator in hydrogen-bonded systems is sensitive to the hydrogen-bonded O-H- -O length, and thus the highest density of hydrogen bond length in THF structure II clathrate was found to be 2.766 and 2.778 Angstrom at 10 and 170 K, respectively. The distribution of hydrogen bond lengths is also briefly discussed.