The study deals with the essence of integration processes and their im- portance in ensuring the development of agrarian and industrial complex. The main factors of the efficiency of integration processes in agriculture are allocated. The review of the authors’ approaches to the integration processesin agrarian and industrial complex of Russia. The mechanisms and tools of regulation of integration processes in agrarian and industrial complex are given. The authors offer methodical approach to the assessment of sustaina- ble development of agrarian and industrial complex taking into account multiplicative effects from inter-territorial (regional and country) and inter- industry interaction on the basis of TOPSIS (the modified method of ordered preference through similarity to ideal decision). The object of study of the authors is agrarian and industrial complex (AIC). As the object of the re- search economic relations connected with the development of integration processes in agrarian and industrial complex and achievement of synergetic effects in agro-food sector of economy act. The research objective is the justi- fication of need of the development of evidence-based approach to creation of effective and deep integration communications for agrarian and industri- al complex of the country. The authors speak about the necessity of the de- velopment of mechanisms of gradual synchronization of elements of system within uniting subjects of agrarian and industrial complex and effective measures of state regulation of specified processes in the direction of the achievement of synergetic effects for the complex.