[en] The answer to these new regulatory challenges was given by implementation of divers measures aimed at strengthening of safety and security of radioactive sources and to prevent the malevolent use of radioactive sources. The international basic safety standards for protection against ionizing radiation and for the safety of radiation sources (B.S.S.) require the establishment and implementation of security measures of radioactive sources to ensure that protection and safety requirements are met. The IAEA has engaged in an extensive effort to establish and/or strengthen national radiation protection and radiological safety infrastructure, including legislation and regulation, a regulatory authority empowered to authorize and inspect regulated activities, an adequate number of trained personnel and technical services that are beyond the capabilities required of the authorized legal persons. The Moroccan authority makes steady efforts to strengthen national radiation safety infrastructure by participating in IAEA model project for upgrading radiation protection infrastructure, to implement the revised version of code of conduct on the safety and security of radioactive sources. Indeed, Morocco expressed its adhesion with the technical assistance project of the IAEA in 2001, carrying on the reinforcement of the national infrastructure of regulation and control of the radioactive materials. The control over radioactive sources is an essential element for maintaining high level of security and safety of radioactive sources. The IAEA T.E.C.-D.O.C.-1388 serves as reference document to implement the control culture. The security problems with which the world is confronted showed that the uses of radioactive sources should subject reinforcements of safety, of control and of security of the radioactive sources. For this purpose, the IAEA launched an action plan for the safety and security of radioactive sources. The IAEA guide Security of radioactive sources will help the national authority in creating a security strategy. Also it is important to disseminate the security culture to prevent the malicious use of radioactive sources. The IAEA in its categorization of the radiation sources published in 2003 recognized that the improvements of security should carry in priority on the radioactive sources which present the greatest risks. The national authority must place the accent on the improvement of the security of the radioactive sources versus an increasing risk of radiological terrorism. Our authority gives a great importance to detect and interdict illicit trafficking in high risk radioactive sources by implementing a series of measures as mentioned in the corresponding IAEA documents. The possibility of the malevolent use of high risk radioactive sources obliges the states to elaborate plans of intervention in the event of radiological emergency. The Moroccan Nuclear Safety Authority (N.S.A.) in its new structure ensures the responsibility relating to safety and security during all stages of the life-cycle of radioactive sources. (authors)