The following factors influence the distribution of population :
1. Fertility of the soil. The states in which there is a large fertile area, the density of population is high. U.P. and Bihar are such states.
2. Amount of rainfall. The density of population is higher in regions of abundant rain. In northern India, the amount of rainfall goes on decreasing from east to west. The density of population also goes on decreasing in the same direction.
3. Climate. Wherever the climate is congenial, the density of population will be high, In Assam even though there is abundant rainfall but the density of population is low because the climate is unhealthy. The malaria is always in an epidemic form.
4. Developed means of transportation. With development of means of transportation the business makes rapid progress and the density of population increases. The reason for high density of population in U.P., Bihar and West Bengal is the development of means of transportation.
5. Industrial development. At places where the factories are located, the density of population also increases. The reason is that people like to live in those areas where industrial development takes place. They can carry on their business more easily in such areas, and they have better chances of earning more money. That is why the density of population is high in Delhi, Mumbai and Kolkata.