Abstract: In order to understand and control the properties of ultrasonic dyeing of wool with neutral dyes,the kinetics and thermodynamics of ultrasonic dyeing of wool were investigated with Lanacron Red S-G.The results indicated that ultrasonic treatment could increase the solubility and decrease the particle size of dyes.When compared with the conventional dyeing under the same temperature,ultrasonic dyeing can not only shorten dyeing time,increase dye up-taking,but also improve diffusion coefficient and dyeing rate.Analysis of the efficiency show that ultrasound facilitates the dyeing process remarkably.