The paper is aimed to present several results of the number of big scale international projects; their purposes were: 1) diagnosis of the contemporary adolescents’ psychological well-being actual level; 2) search of the ways to improve this level. Adolescent psychological well-being actual level has been monitored on different experimental fields in Russia, Ukraine, and Kyrgyzstan. After that multifactor intervention (with adolescents, their parents, teachers, and school administration) took place. The study results achieved demonstrate the intervention strategy efficacy and productivity, and allow defining a direction of further movement.