The study of the or unsaturated soil mechanics, began in the70s, where some of the fundamental concepts and theories were formulated. At the present time, this concepts and theories have not been implemented in practice and much less as part of the training in civil engineering programs and related areas. This article presents the introductory concepts of partially saturated soil mechanics, from the development of an appropriate theoretical framework for the soil behavior in the condition of unsaturated, including stress state variables and the shear strength equation, and the methods for measurement of soil suction. The presentation of these basic concepts in the university classroom is an important contribution to achieve its implementation and to move from theory to practice.