Abstract: After discussion of the sampling technique by using a fixed piston thin wall sampler an analysis is given on the test resut of soft clay from Harbours of Lianyungang and Chiwan,and the Guang-Shen Express Highway in this paper.It is indicated that the mechanical properties of solf clay determined in laboratory are influenced remarkably by the disturbance of soil samples,but the influence of sampling disturbance on the value of physical parameters is not significant.It is convincingly ghown by the study that high quality samples can be obtained with the thin wall sampler provided that the sampling is done strictly according to the operating instruction,while the samples obtained with conventional thick wall open drive tube sampler are often seriousjy disturbed.