In developed countries, the population growth rate have almost stopped and moreover the population of old people have increased. On the other hand in non-developed and developing countries, the population growth rate is high and uneducated. All these cause various economical problems and social instability, that is why it is considered as an important problem today.Within the historical period, classical and modern economists have developed different approaches. The classical economists have developed different theories related with the relation between economical structure and population, social structure, technological development, geographical structure and religious beliefs. While the classical economists were concerned about capital-land population ratio, national security, while modern economists have considered the issue differently together with the industrial revolution and the strengthening of human rights expression. The modern economists developed population theories and policies where the concern is to reach the optimum population ratio, assuming that all lands in the world have found their owners, capital – land / population ratio have been reduced, it is impossible to add new agricultural lands to the production, land units are not necessary for national security and taking human rights and women rights paradigms into consideration.