Abstract: There are two kinds of classification systems for fine soil in China. One is based on the plasticity chart by means of the liquid limit and the plasticity index. The other is only based on the plasticity index. Furthermore, the two systems have different standard for determining the plasticity index, and some confusion is caused in engineering practice. The historical causes for the two kinds of classification systems for fine soil in China are investigated. The current international classification standards or systems for fine soil are analyzed and compared. Some suggestions are proposed for the unified classification system for fine soil in China.