This article brings forward an actual problem for our society: aggressiveness. Last years aggressiveness is studied by researches from different areas. Our article demonstrates that the structure of aggressive behavior depends on gender and age. The manifestation of aggressive behavior differs from on age to another. As physical force is increasing in preadolescence aggressive behavior can become more severe. Nowadays the increasing number of the disintegrated families, the insufficient affectivity from pa-rents, the freedom education have an impact on preadolescents personality and can influence the appea-rance of hostility and aggressiveness. Preadolescence is the age of numerous changes and transition to ma-turity this explains that aggressiveness is an answer of preadolescent to various difficulties that preado-lescents deal with. The types of aggressive behavior depend on gender and preadolescents background.