A short review is made of t he présent status of the three methods of radio active dating applicable to common rock types. Thèse methods rest upon the dis integration schemes of uranium, rubidium and potassium respectively. Their respective fields of apphcation in geochronology are considered and discussed as well as the kind of geological information that they can provide, in addition to âge estimâtes. At présent thèse radioactive methods are widely used and should no longer be considered by geologists as a branch of physics; geochronology is now truly part of the earth sciences.