The mechanism of solute incorporation into an ice-layer in freeze concentration with ice-lining was studied by changing the impeller speed N and the difference between the brine temperature and the freezing point of the feed solution Delta T in 10 kg/m(3) CCNa solution. The effect of N on the apparent partition coefficient of the solute K, is more serious than that of Delta T. The growth rate of the ice layer is 10(-7)similar to 10(-6) m/s under the condition of Delta T = 2.8 similar to 7.9 degrees C and N=20 similar to 400 min(-1). The growth rate had a little effect on solute incorporation into the ice-layer. K values depended on the surface condition of the ice layer, which is effected by the mixing speed of the impeller. The ice layer formed at low mixing speed has a complex rough shape, and has much solute because of adhesion to a large surface area. Therefore, it is recommended that freeze concentration is performed by making an ice layer with smooth surface at high mixing speed.