The purpose of our research is to reveal how various forms of aggression affect the types of interpersonal relations between teenagers learning in mono and multi ethnic environment. Aggression was diagnosed with the Buss-Durkee Hostility Inventory (BDHI); the type of interpersonal relations was determined by Timothy Leary's Interpersonal Behavior Circle Personal Inventory (the "Leary" Personality Test). Differences in the forms of aggression showed by teenagers learning in mono and multi ethnic environment were identified with the Student's t-test; relationship between forms of aggression and types of interpersonal relations were identified with the Spearman Rank-Order Correlation (p). The sample involved 236 teenagers between the ages of 13.5-15. The study revealed differences between forms of aggression showed by teenagers learning in mono and multi ethnic environment such as indirect aggression, negativism, guilt and suspicion. Correlation analysis revealed differences in the relationship between forms of aggression such as assault aggression, indirect aggression, guilt and types of interpersonal relationships. It was found that the multiethnic composition of micro-society reduces the manifestation of many forms of aggression among teens, increases the sense of guilt and does not affect any type of interpersonal relationships.