Abstract: Hollow cylinder apparatus(HCA) is the main equipment for the study of principal stress rotation.Nowadays the main reason for few studies on the research of intact samples was due to the difficulties of sampling.Based on researches and tests,the sample size of 5 Hz HCA in Zhejiang University was determined.Sample kits for soft clay,especially the cutting head and refinishing kit for inner wall preparation,were invented and proved to be successful.Details of cutting procedures and installation of sample were introduced.The present method of sample preparation provided a useful way to make suitable samples for HCA test.