This thesis aimed to study the distribution of different cohabitation types in the Czech Republic and their development over time in relation to the prevalence of cohabitation. Furthermore, it also aimed to examine the stratification of each cohabitation type. Analysing data from the Generations and Gender Survey from 2005 and 2021 for Czechia, I found that cohabitation types that serve as marriage forerunners dominate in both observed periods, despite the increasing prevalence of cohabitation in the population. Furthermore, cohabitation types proved to be stratified by age, education, and sex.