Social concern in promoting social competencies and skills was recently demonstrated in the Educational System Reform which includes in all levels of compulsory schooling, transverse topics such as Moral Education and Education for Peace. After revising different models of school primary prevention, a situational model of Social Competence is presented. In this model, different skills are integrated: Negotiation, Assertion and Prosociality. Training in underlying processes and situational references of these 'skills' is the general aim of our research line. Description of our Program, intervention procedures and assessment instruments were introduced briefly in this work.