The population study is valuable in the field of economics. The study of population trends and economic growth is related to the relationship between economics and demography in the field of population and development, manpower studies, the economics of fertility, and comprehensive economic-demographic models. The number and quality of population which exists on the earth depends greatly on the economic opportunities and economic organization. Population growth, size and distribution cannot be discussed separately without the economic growth or change. Demography and economics are closely related in the fields of variables like, rate of population growth, age, sex, educational level, profession, per capita income and national income. Both emigration and immigration creates wide-spread economic change. The influence of population upon economic is more important in developing and undeveloped countries then the influence of population in the developed countries. Population growth creates demands of people for goods and supply. This demand influences economic factors including labor supply, employment and investment etc. the decreasing rate of population and migration into new areas for habitation influence the investment in the economic market. Population faces serious economic problems which is due to the retarding rate of progress in economy and supply of labor. Population growth is the first condition for economic development. The influence of population on economic development has been analyzed in the theory of demographic transition. The relation between demography and economics is the closest but both are the independent sciences today.