Liquid-limit is used as one of the most important characteristics to judge the physical properties of soill. Presently, nevertheless, we do not have any complete methods for measuring Liquid-limit. The fall-cone method is well known by its simple operation and high accuracy of measurement. In this paper it is discussed the applicability of the above method to the examination of sand mattel clay. The following results were obtained. The relation between the value of con-penetration and the moisture content shows linear change on the both-logrithmic paper. Moreover, the constant values of cone-penetration corresponding to each Lipuid-limit were obtained.