Abstract: First, this paper presents experimental results of correlation between shear wave velocity and degree of consolidation during primary consolidation of soft clays in Zhejiang coastal area. The ratio of increment of shear wave velocity at any time during primary consolidation to stress ratio, △vs/(△p’/p’), is proportional to the degree of consolidation, which provides scientific basis for monitoring the consolidation of soft clay foundation improved by sand-drain and other techniques using in-situ shear wave velocity measurement. Secondly, a case study of open-air coal storage stablized by sand-drain in Zhcaghai Power Plant is presented. Comparison of degree of consolidation evaluated by dissipation of excessive pore water pressure with that predicted by shear wave velocity measurement by cross-hole technique is made, which shows the method proposed by the authors in the paper is promising in practical engineering application.