Introduction. The study of religious radicalisation is an important aspect of counteracting the incitement of hostility between different groups and communities and reducing the level of violence in Russian society. Modern scientific ideas are characterised by multiple meanings that do not effectively counteract the negative impact on young people’s attitudes towards religion and the believers. Academic literature describes concepts and models of radicalisation that differ in theoretical and methodological foundations, based mainly on the material of foreign studies. This situation makes it impossible to develop a construct of radicalisation that could be operationalised for diagnosing the risk of religious radicalisation of Russian youth.
 The purpose of the research is to verify the theoretical model (construct) of religious radicalisation, as well as to develop a questionnaire based on it, which makes it possible to measure the risk of religious radicalisation of young people through the study of attitudes towards religion and believers.
 It is supposed that religious radicalisation is formed under the influence of the social environment on the subject’s perceptions of the importance of religion and believers for society and the state. Based on the analysis of theoretical knowledge about radicalisation, facts and information about the activities of destructive religious and extremist communities, a model of religious radicalisation is proposed, including six statements: about the exclusive importance of religion, religious leaders and believers (sacralisation and clericalisation), the need to protect them from changes, interference of non-believers or representatives of another religion (fundamentalism and xenophobia), to maintain relations only with representatives of a particular religious association, including in matters of education, cultural and social development, ignoring or failing to comply with obligations, laws and regulations (socialisation and discrimination).
 Methodology, methods and techniques. The methodological basis of the research is the socio-psychological approach in the study of human cognition of society (G.M. Andreeva), empirical concepts of religious radicalisation of individuals and groups (A.W. Kruglanski, N. Ellemers, A. R. Schmidt, etc.).
 The empirical research is aimed at testing the theoretical model of religious radicalisation; development and verification of a questionnaire to study the risk of religious radicalisation.
 The method of data collection is the questionnaire «Religious radicalisation», structurally corresponding to the theoretical model of radicalisation, including 90 questions grouped into six scales, as well as indicators of religious self-determination and religious behavior.
 Results processing method: descriptive statistics, correlation, one-factor analysis of variance and confirmatory analysis.
 Research sample: 874 people divided into Russian (n=336 people), Kyrgyz (268 people) and Uzbek (n=270 people) sub-samples of young people.
 Results: by means of confirmatory factor analysis of the results of the survey of national samples, the theoretical model of youth radicalisation was corrected. A three-factor empirical model was found to have the best structural characteristics for the Russian sample (χ2=216.5, df=87, p<0.0001, RMSEA=0.067, p=0.008 (RMSEA CI 90% = 0.056-0.078), CFI=0.949, TLI=0.95). The model consists of three scales from the theoretical model (‘Clericalisation’, ‘Discrimination’, ‘Xenophobia’) but includes statements from other scales from the theoretical model (‘Sacralisation’, ‘Fundamentalism’, ‘Socialisation’).
 The second result was the verification of a questionnaire to study the risk of religious radicalisation among Russian youth. The questionnaire consists of 15 statements, grouped into three scales, has satisfactory reliability values according to the internal consistency criterion and intercorrelations (Cronbach’s α «Clericalisation» = 0.89, r=0.63, p<0.001; «Discrimination» = 0.76, r=0.38, p<0.001; Xenophobia = 0.81, r=0.46, p<0.001).
 Scientific novelty. The received results expand the idea of socio-psychological preconditions of religious radicalisation, demonstrate a set of beliefs that can stimulate intolerant attitude of young people to religion and believers.
 Practical significance. The presented methodology can be used for research purposes to study the preconditions of religious radicalisation of young people.