The fertility rate in Southeast and South Asia is relatively high compared to other region in the world, but the trend tends to decrease rapidly. This paper aims to quantitatively explore the factors influencing fertility rate in Southeast and South Asia by applying econometric model of the panel data. Applying the fixed effect estimation method on the 2003-2008 panel data, this study found that the infant mortality rate is an important factor influencing the high fertility rate in this area. The high elasticity of infant mortality rate implies that parents cover their risk from losing children by producing more children. Surprisingly, the demand for children (fertility rate) follows the demand of normal goods in which one digit increase in log income per capita will increase the fertility rate by 0.334 births per woman.