The absorption spectrum of oxygen-17-enriched water vapor in the 12,055–12,260 cm−1 region was recorded with a continuous-wave cavity ring-down spectrometer (CW-CRDS) at room temperature. In total, 1342 lines were observed in this region, while more than 1400 absorption transitions were assigned based on previously published experimental energies and the variational calculations based on the results of Partridge and Schwenke. The typical frequency accuracy of 0.002 cm−1 was achieved in this work. Three hundred and fifty-eight ro-vibrational energy levels of H217O water isotopologue were retrieved, which belong to the ν1+12ν2+ν3=3.5 and 4 polyads: (0 1 3), (0 3 2), (1 1 2), (1 3 1), (2 1 1), (2 2 1), (2 3 0), (3 0 1), and (3 1 0) states. One hundred and ten of them were reported for the first time. Comparisons of experimental line positions with those in the HITRAN database were given for H216O and H217O isotopologues. The obtained vibration-rotation energy levels were also compared with MARVEL values.