In this article the importance of assertive communication in multi-ethnic environment and polyculture is presented. Assertivity is a complex psychosocial phenomenon termed as the ability to self-promotion and asserting capabilities, to express oneself fillings and beliefs without over anxiety, to protect oneself rights without hurting the others. The assertivity dialogue competence is a component of the social competence. The great value has competence formation of assertivity dialogue in the polyethnic environment. In the article reveal prominent aspects of communicative assertivity competence formation process.