This work deals with the ethnic differentiation of marital behavior in Kazakhstan. The study of marital behavior of ethnic groups is important and necessary, especially in a multiethnic state as Kazakhstan. Undoubtedly, the institution of marriage regulates the social reproduction of the population, and differences in marital behavior have an impact on family organizations and fertility among ethnic groups. These differences may shape the age at first marriage, age at first birth, and so on, that will have subsequent effects on the family organization among these ethnic groups. This work attempts to analyze the differences in attitudes toward marital marital myths between ethnic Kazakhs and Slavics. The sociological research has revealed some significant differences in the myths existing about marriage between these ethnic groups. These differences, largely due to socio-cultural characteristics.