The engineering mechanical properties of the soil are under the influence of the various factors. The microstructure character of the soil is one of the main factors
concerned by engineering technicians and scientists in recent years. In this paper
the historical development of the microstructure research for the soil is simply retraced. It is mentioned that some contents and results of microstructure research in foreign country and the research results of various representive soil of recent years in our country. Furthermore
the viewpoints about the further research of the microstructure is proposed by the author.