Abstract：Soil is assembly of many minerals with multiphases. Soil is easy to change and has many shapes. It is from experiments that people began to learn the knowledge about soil mechanics. In other words，the formation and development of the soil mechanics theory is linked closely to the methodology of experiments. Some modern techniques，such as SEM and CT，have emerged in recent years and have greatly improved the study of soil microstructure，which are hot tropics today. In this paper，the characteristics of the experiments approach for soil mechanics is analyzed. Based on the analysis of characteristics of experiments methods，the modern physical simulation experiments，such as SEM and CT，can also be used in description of constitutive model of soil. And a new scientific method——virtual technology，which can show the transfer and the reaction of influential factors under additional stress in complex condition，is discussed in the paper. This is a new approach for establishing constitutive model of soil，and interests more and more scientists and engineers.
