Tidal currents and tidal residual currents in Chinhae Bay are investigated by the field observations and hydraulic experiments during the spring tide and neap tide. The horizontal and vertical scales of the model are l/2,000 and 1/159, respectively. The hydraulic model results roughly coincide with the field data. Maximum tidal currents during the spring tide and neap tide in the central channel of Chinhae Bay are strong as about 90 and 30cm/s respectively, and strong tidal residual currents take place. Maximum tidal currents during the spring tide and neap tide in the western and northern part of the bay are weak as below 30 and 10cm/s respectively, and also tidal residual currents are weak. Tidal residual currents rotating clockwise occur in the central part of the bay. Northward tidal residual currents in the northern part of Kajo-do are predominant, whereas southward ones in the southern part of Kajo-do are remarkable. The surface currents in the bay depend strongly on the wind and river flow, and it seems to be remarkable during the neap tide.