This article is bringing important explanations about the “Preventive Criminology” chapter, especially for the “penal politics” notion and on the “criminology” subject. And in the way to make the purport much clearer, both of the mentioned notions are studied in complicity. Also, there is reminded, with strong facts about what a minutely process is the “criminology research”, describing it stage by stage. As well, the author detected serious changes toward the crime meaning. He explains the new policies of crime and how to make the crimes easier to prevent. In conclusion, a batch of steps are encouraged in the way to improve the fight against crime.