In recent decades, the institution of the family in Iran has undergone 
significant changes. Such as: change in the formation of marriage and 
family formation, increase in marriage age, decrease in marriage rate, 
increase in definite celibacy, change in the circle of marriage, change in 
criteria for marriage and change in childbearing aƫtudes. Many experts 
do not consider the changes in the family institution as the result of 
changes in the economic situation and the institutional structure of 
society, but also believe that these changes stem from changes in the 
process of values and traditions.
The theoretical basis of this research is based on ideological and 
aƫtude theories. According to Inglehart theory of cultural and value 
transformation and Ven de kaa and Lasthaeghe theory in the framework 
of the second population transition theory, two aspects of value and 
aƫtude changes in the country including individualism and family values 
and their impact on change in criteria and methods of marriage, aƫtude 
to the appropriate age for marriage and the desired number of children 
are considered. The required data are taken from the findings of two 
naƟonal family surveys (2019) and the third wave of Iranian values and 
aƫtudes (2015), which have been evaluated by secondary analysis. 
Findings showed that the rate of childbearing in Iran in the last four 
decades has increased from normal natural (7.1 children) to voluntary 
ferƟlity and below the replacement level (1.7 children) and the average 
age of marriage for boys and girls, has been accompanied by an increase 
of about 5 years. Values and aƫtudes about marriage and childbearing 
and the degree of individualism differed between the three generations 
of young, middle-aged and older. On the other hand, aƫtudes toward 
the desired child and the appropriate age for marriage are significantly correlated with the degree of individualism. Therefore, the effect of cultural factors on changes in marriage and childbearing in Iran can be 
confirmed. And more emphasis should be placed on cultural factors to 
revise population policies.