Observations of high-frequency (HF) Pn phases by an oceanbottom seismometer (OBS) array were made at distances between 6¿ and 18¿ in the north-western Pacific. At this distance range, mantle-refracted P phases arrive earlier than HF-Pn phases. These two phases are successfully separated for near surface earthquakes by applying appropriate filtering, since the dominant frequencies of HF-Pn phases are higher than 6 Hz and the frequencies of mantle-refracted P phases are rather low, about 3 Hz. The apparent velocities of HF-Pn phases in this distance range are estimated to be from 8.3 to 8.1 km/sec or even lower, while those of mantle-refracted P waves are from 8.4 to 8.6 km/sec. The reported value of 8.33 km/sec for Hf-Pn phases appears to be an average of both HF-Pn and mantle-refracted P phases. Therefore, these observations suggest that a proposed additional HF-Pn wave guide for the higher velocity of 8.33 kms/sec is questionable.