ENGLISH ABSTRACT This thesis deals with sexual behavior of young people from fifteen till twenty-five years in the Czech Republic. Their activities are evaluated and interpreted from anthropological perspective of passage rituals. The official passage rituals of adulthood were eliminated in the western society and one universal passage ritual was crumbled in inexhaustible assemblage of particular unofficial hazy and often unclear ritual actions. This transformation begins because the man is according to Mary Douglas a ritual animal and the ritual suppressed in one form appears in another on even stronger. In this large assemblage of passage rituals of adulthood we can include for example dancing courses, school- leaving examination, gaining of the driving licence, smoking, drinking alcohol or just sexual activity. In the period of adolescence we can mark this activity as ritual because it has not the clear utilitarian procreative aim. This work presents original field research which bears on two main pillars: 1. on the quantitative questionnaire investigation and 2. on qualitative questionnaire investigation. The quantitative research was made in the secondary schools in Pilsen region and its main part count one hundred-eighty eight respondents. The research was going on during the year 2008 - 2009. The...