Surface currents to the east of Okinawa Island were observed by using HF (high-frequency) ocean radars in August--September 1995. During that period, a typhoon passed near the observation area, and the horizontal variability of near-inertial oscillations associated with the typhoon passage was estimated. In addition, the near-inertial amplitudes and horizontal wave number vectors were estimated. These estimations showed that the near-inertial amplitude was large in the offshore area and small near the coast. The maximum near-inertial wavelength was estimated to be in the order of 1000 km, and the near-inertial wave direction was southward and changed to northwestward on 23 August in 1995. A slab model, incorporating low-frequency currents, was used to calculate near-inertial currents. It was found that the amplitude of calculated near-inertial oscillations was also large in the offshore area. Moreover, the phase-propagation direction of the near-inertial waves was southward and changed to northwestward or westward on 22 August. The growth rate obtained from the dispersion relation was large in the offshore area, where the near-inertial amplitude was large.