Abstarct: This research investigates the relationship between fertility rate and human capital and economic development in 21 selected provinces of Iran during the period from 1966 to 2017. For this purpose, the method of estimating multiple indices - multiple causes with structural equation modeling approach (MIMIC method) has been used. Research findings show that human capital has a positive effect on economic development, which has a positive statistical effect on human capital, but fertility has a negative relation with human capital, thus confirming the hypothesis of the causal relationship between fertility rate and human capital. With the increase in economic development, the Gini coefficient decreases, which is statistically significant . The positive impact of total human capital on the share of employment in the meaningful industrial sector is also. Human development increases the urbanization rate, which is statistically confirmed. Human capital has a positive and significant effect on other variables of the model such as per capita income, Gini coefficient, except for the statistically meaningless female participation rate.